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ETV6 dependency in Ewing sarcoma by antagonism of EWS-FLI1-mediated enhancer activation. Nat Cell Biol 2023; 25:298-308. [PMID: 36658219 PMCID: PMC10101761 DOI: 10.1038/s41556-022-01060-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Accepted: 11/24/2022] [Indexed: 01/21/2023]
Abstract
The EWS-FLI1 fusion oncoprotein deregulates transcription to initiate the paediatric cancer Ewing sarcoma. Here we used a domain-focused CRISPR screen to implicate the transcriptional repressor ETV6 as a unique dependency in this tumour. Using biochemical assays and epigenomics, we show that ETV6 competes with EWS-FLI1 for binding to select DNA elements enriched for short GGAA repeat sequences. Upon inactivating ETV6, EWS-FLI1 overtakes and hyper-activates these cis-elements to promote mesenchymal differentiation, with SOX11 being a key downstream target. We show that squelching of ETV6 with a dominant-interfering peptide phenocopies these effects and suppresses Ewing sarcoma growth in vivo. These findings reveal targeting of ETV6 as a strategy for neutralizing the EWS-FLI1 oncoprotein by reprogramming of genomic occupancy.
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Koppenhafer SL, Goss KL, Voigt E, Croushore E, Terry WW, Ostergaard J, Gordon PM, Gordon DJ. Inhibitor of DNA binding 2 (ID2) regulates the expression of developmental genes and tumorigenesis in ewing sarcoma. Oncogene 2022; 41:2873-2884. [PMID: 35422476 PMCID: PMC9107507 DOI: 10.1038/s41388-022-02310-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 03/29/2022] [Accepted: 03/31/2022] [Indexed: 11/24/2022]
Abstract
Sarcomas are difficult to treat and the therapy, even when effective, is associated with long-term and life-threatening side effects. In addition, the treatment regimens for many sarcomas, including Ewing sarcoma, rhabdomyosarcoma, and osteosarcoma, are relatively unchanged over the past two decades, indicating a critical lack of progress. Although differentiation-based therapies are used for the treatment of some cancers, the application of this approach to sarcomas has proven challenging. Here, using a CRISPR-mediated gene knockout approach, we show that Inhibitor of DNA Binding 2 (ID2) is a critical regulator of developmental-related genes and tumor growth in vitro and in vivo in Ewing sarcoma tumors. We also identified that homoharringtonine, which is an inhibitor of protein translation and FDA-approved for the treatment of leukemia, decreases the level of the ID2 protein and significantly reduces tumor growth and prolongs mouse survival in an Ewing sarcoma xenograft model. Furthermore, in addition to targeting ID2, homoharringtonine also reduces the protein levels of ID1 and ID3, which are additional members of the ID family of proteins with well-described roles in tumorigenesis, in multiple types of cancer. Overall, these results provide insight into developmental regulation in Ewing sarcoma tumors and identify a novel, therapeutic approach to target the ID family of proteins using an FDA-approved drug.
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Affiliation(s)
- Stacia L Koppenhafer
- Department of Pediatrics, Division of Pediatric Hematology/Oncology, University of Iowa, Iowa City, IA, 52242, USA
| | - Kelli L Goss
- Department of Pediatrics, Division of Pediatric Hematology/Oncology, University of Iowa, Iowa City, IA, 52242, USA
| | - Ellen Voigt
- Carver College of Medicine, University of Iowa, Iowa City, IA, 52242, USA
| | - Emma Croushore
- Department of Pediatrics, Division of Pediatric Hematology/Oncology, University of Iowa, Iowa City, IA, 52242, USA
| | - William W Terry
- Department of Pediatrics, Division of Pediatric Hematology/Oncology, University of Iowa, Iowa City, IA, 52242, USA
| | - Jason Ostergaard
- Department of Pediatrics, Division of Pediatric Hematology/Oncology, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Peter M Gordon
- Department of Pediatrics, Division of Pediatric Hematology/Oncology, University of Minnesota, Minneapolis, MN, 55455, USA
| | - David J Gordon
- Department of Pediatrics, Division of Pediatric Hematology/Oncology, University of Iowa, Iowa City, IA, 52242, USA.
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3
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Oncogenes, Proto-Oncogenes, and Lineage Restriction of Cancer Stem Cells. Int J Mol Sci 2021; 22:ijms22189667. [PMID: 34575830 PMCID: PMC8470404 DOI: 10.3390/ijms22189667] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2021] [Revised: 09/02/2021] [Accepted: 09/06/2021] [Indexed: 01/03/2023] Open
Abstract
In principle, an oncogene is a cellular gene (proto-oncogene) that is dysfunctional, due to mutation and fusion with another gene or overexpression. Generally, oncogenes are viewed as deregulating cell proliferation or suppressing apoptosis in driving cancer. The cancer stem cell theory states that most, if not all, cancers are a hierarchy of cells that arises from a transformed tissue-specific stem cell. These normal counterparts generate various cell types of a tissue, which adds a new dimension to how oncogenes might lead to the anarchic behavior of cancer cells. It is that stem cells, such as hematopoietic stem cells, replenish mature cell types to meet the demands of an organism. Some oncogenes appear to deregulate this homeostatic process by restricting leukemia stem cells to a single cell lineage. This review examines whether cancer is a legacy of stem cells that lose their inherent versatility, the extent that proto-oncogenes play a role in cell lineage determination, and the role that epigenetic events play in regulating cell fate and tumorigenesis.
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MYB oncoproteins: emerging players and potential therapeutic targets in human cancer. Oncogenesis 2021; 10:19. [PMID: 33637673 PMCID: PMC7910556 DOI: 10.1038/s41389-021-00309-y] [Citation(s) in RCA: 81] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Revised: 02/05/2021] [Accepted: 02/10/2021] [Indexed: 01/31/2023] Open
Abstract
MYB transcription factors are highly conserved from plants to vertebrates, indicating that their functions embrace fundamental mechanisms in the biology of cells and organisms. In humans, the MYB gene family is composed of three members: MYB, MYBL1 and MYBL2, encoding the transcription factors MYB, MYBL1, and MYBL2 (also known as c-MYB, A-MYB, and B-MYB), respectively. A truncated version of MYB, the prototype member of the MYB family, was originally identified as the product of the retroviral oncogene v-myb, which causes leukaemia in birds. This led to the hypothesis that aberrant activation of vertebrate MYB could also cause cancer. Despite more than three decades have elapsed since the isolation of v-myb, only recently investigators were able to detect MYB genes rearrangements and mutations, smoking gun evidence of the involvement of MYB family members in human cancer. In this review, we will highlight studies linking the activity of MYB family members to human malignancies and experimental therapeutic interventions tailored for MYB-expressing cancers.
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Picchiarelli G, Dupuis L. Role of RNA Binding Proteins with prion-like domains in muscle and neuromuscular diseases. Cell Stress 2020; 4:76-91. [PMID: 32292882 PMCID: PMC7146060 DOI: 10.15698/cst2020.04.217] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
A number of neuromuscular and muscular diseases, including amyotrophic lateral sclerosis (ALS), spinal muscular atrophy (SMA) and several myopathies, are associated to mutations in related RNA-binding proteins (RBPs), including TDP-43, FUS, MATR3 or hnRNPA1/B2. These proteins harbor similar modular primary sequence with RNA binding motifs and low complexity domains, that enables them to phase separate and create liquid microdomains. These RBPs have been shown to critically regulate multiple events of RNA lifecycle, including transcriptional events, splicing and RNA trafficking and sequestration. Here, we review the roles of these disease-related RBPs in muscle and motor neurons, and how their dysfunction in these cell types might contribute to disease.
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Affiliation(s)
- Gina Picchiarelli
- Université de Strasbourg, INSERM, Mécanismes Centraux et Périphériques de la Neurodégénérescence, UMR_S 1118, Strasbourg, France
| | - Luc Dupuis
- Université de Strasbourg, INSERM, Mécanismes Centraux et Périphériques de la Neurodégénérescence, UMR_S 1118, Strasbourg, France
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6
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Hui S, Guo-Qi Z, Xiao-Zhong G, Chun-Rong L, Yu-Fei L, Dong-Liang Y. IMP3 as a prognostic biomarker in patients with malignant peritoneal mesothelioma. Hum Pathol 2018; 81:138-147. [PMID: 30031101 DOI: 10.1016/j.humpath.2018.07.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Revised: 07/02/2018] [Accepted: 07/03/2018] [Indexed: 02/08/2023]
Abstract
Malignant peritoneal mesothelioma (MPeM) is an incurable cancer with poor prognosis, and several biomarkers have been suggested for screening of MPeM. The aim of our study was to evaluate the prognostic significances of IMP3 and Fli-1 in MPeM. Diagnostic biopsies of 44 MPeM patients were centrally collected and were immunohistochemically analyzed for expression of IMP3, Fli-1, and Ki-67. Labeling was assessed by 2 pathologists. Complete clinical information and follow-up were obtained from patients' records. Carcinomas expressed Fli-1 in 42 (95.5%) of 44 specimens, and IMP3 in 23 (52.3%) of 44 specimens. Spearman ρ analysis revealed that Fli-1 expression was related to both histologic type and Ki-67 labeling index (Ki-67LI; r = -0.500, P < .05; r = 0.358, P < .05), and IMP3 expression was related to Ki-67LI (r = 0.401, P < .05). A Kaplan-Meier analysis and univariate Cox regression analysis showed that tumor-directed treatment, a lower peritoneal carcinomatosis index, stage I, lower Ki-67LI, and lower level of IMP3 expression had a statistically significantly positive effect on overall survival; Fli-1 did not affect overall survival in the univariate analysis (hazard ratio [HR], 1.026; P = .904). A Kaplan-Meier analysis showed the correlation between IMP3-Fli-1 and overall survival, whereas univariate and multivariate Cox regression analyses did not confirm the correlation. Cox regression analysis revealed that IMP3 expression (HR, 2.311 [95% confidence interval, 1.190-4.486]; P = .013) and no tumor-directed treatment (HR, 0.189 [95% confidence interval, 0.086-0.416]; P = .000) retained independent prognostic significance, both with negative effect on OS. IMP3, along with tumor-directed treatment protocols, is a powerful prognosticator in patients with MPeM.
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Affiliation(s)
- Song Hui
- Department of Gastroenterology, Cangzhou Central Hospital, Cangzhou, Hebei 061001, China
| | - Zheng Guo-Qi
- Department of Gastroenterology, Cangzhou Central Hospital, Cangzhou, Hebei 061001, China.
| | - Guo Xiao-Zhong
- Department of Pathology, Cangzhou Central Hospital, Cangzhou, Hebei 061001, China
| | - Liu Chun-Rong
- Department of Pathology, Cangzhou Central Hospital, Cangzhou, Hebei 061001, China
| | - Liang Yu-Fei
- Department of Gastroenterology, Cangzhou Central Hospital, Cangzhou, Hebei 061001, China
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Acquisition of an oncogenic fusion protein is sufficient to globally alter the landscape of miRNA expression to inhibit myogenic differentiation. Oncotarget 2017; 8:87054-87072. [PMID: 29152063 PMCID: PMC5675615 DOI: 10.18632/oncotarget.19693] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Accepted: 07/03/2017] [Indexed: 01/07/2023] Open
Abstract
The differentiation status of tumors is used as a prognostic indicator, with tumors comprised of less differentiated cells exhibiting higher levels of aggressiveness that correlate with a poor prognosis. Although oncogenes contribute to blocking differentiation, it is not clear how they globally alter miRNA expression during differentiation to achieve this result. The pediatric sarcoma Alveolar Rhabdomyosarcoma, which is primarily characterized by the expression of the PAX3-FOXO1 oncogenic fusion protein, consists of undifferentiated muscle cells. However, it is unclear what role PAX3-FOXO1 plays in promoting the undifferentiated state. We demonstrate that expression of PAX3-FOXO1 globally alters the expression of over 80 individual miRNA during early myogenic differentiation, resulting in three primary effects: 1) inhibition of the expression of 51 miRNA essential for promoting myogenesis, 2) promoting the aberrant expression of 43 miRNA not normally expressed during myogenesis, and 3) altering the expression pattern of 39 additional miRNA. Combined, these changes are predicted to have an overall negative effect on myogenic differentiation. This is one of the first studies describing how an oncogene globally alters miRNA expression to block differentiation and has clinical implications for the development of much needed multi-faceted tumor-specific therapeutic regimens.
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9
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Eid JE, Garcia CB. Reprogramming of mesenchymal stem cells by oncogenes. Semin Cancer Biol 2014; 32:18-31. [PMID: 24938913 DOI: 10.1016/j.semcancer.2014.05.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2014] [Revised: 05/21/2014] [Accepted: 05/22/2014] [Indexed: 12/18/2022]
Abstract
Mesenchymal stem cells (MSCs) originate from embryonic mesoderm and give rise to the multiple lineages of connective tissues. Transformed MSCs develop into aggressive sarcomas, some of which are initiated by specific chromosomal translocations that generate fusion proteins with potent oncogenic properties. The sarcoma oncogenes typically prime MSCs through aberrant reprogramming. They dictate commitment to a specific lineage but prevent mature differentiation, thus locking the cells in a state of proliferative precursors. Deregulated expression of lineage-specific transcription factors and controllers of chromatin structure play a central role in MSC reprogramming and sarcoma pathogenesis. This suggests that reversing the epigenetic aberrancies created by the sarcoma oncogenes with differentiation-related reagents holds great promise as a beneficial addition to sarcoma therapies.
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Affiliation(s)
- Josiane E Eid
- Department of Cancer Biology, Vanderbilt University Medical Center, 771 Preston, Research Building, 2220 Pierce Avenue, Nashville, TN 37232, USA.
| | - Christina B Garcia
- Department of Pediatrics-Nutrition, Baylor College of Medicine, BCM320, Huston, TX 77030, USA
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IRE1a constitutes a negative feedback loop with BMP2 and acts as a novel mediator in modulating osteogenic differentiation. Cell Death Dis 2014; 5:e1239. [PMID: 24853417 PMCID: PMC4047903 DOI: 10.1038/cddis.2014.194] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2014] [Revised: 03/27/2014] [Accepted: 03/31/2014] [Indexed: 12/27/2022]
Abstract
Bone morphogenetic protein 2 (BMP2) is known to activate unfolded protein response (UPR) signaling molecules, such as BiP (IgH chain-binding protein), PERK (PKR-like ER-resistant kinase), and IRE1α. Inositol-requiring enzyme-1a (IRE1a), as one of three unfolded protein sensors in UPR signaling pathways, can be activated during ER stress. Granulin-epithelin precursor (GEP) is an autocrine growth factor that has been implicated in embryonic development, tissue repair, tumorigenesis, and inflammation. However, the influence on IRE1a in BMP2-induced osteoblast differentiation has not yet been elucidated. Herein we demonstrate that overexpression of IRE1a inhibits osteoblast differentiation, as revealed by reduced activity of alkaline phosphatase (ALP) and osteocalcin; however, knockdown of IRE1a via the RNAi approach stimulates osteoblastogenesis. Mechanistic studies revealed that the expression of IRE1a during osteoblast was a consequence of JunB transcription factor binding to several AP1 sequence (TGAG/CTCA) in the 5'-flanking regulatory region of the IRE1a gene, followed by transcription. In addition, GEP induces IRE1a expressions and this induction of IRE1a by GEP depends on JunB. Furthermore, IRE1a inhibition of GEP-induced osteoblastogenesis relies on JunB. Besides, GEP is required for IRE1a inhibition of BMP2-induced bone formation. Collectively, these findings demonstrate that IRE1a negatively regulates BMP2-induced osteoblast differentiation and this IRE1a inhibition effect depends on GEP growth factor. Thus, IRE1a, BMP2, GEP growth factor, and JunB transcription factor form a regulatory loop and act in concert in the course of osteoblastogenesis.
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11
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Functions of heterogeneous nuclear ribonucleoproteins in stem cell potency and differentiation. BIOMED RESEARCH INTERNATIONAL 2013; 2013:623978. [PMID: 23984388 PMCID: PMC3745930 DOI: 10.1155/2013/623978] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/29/2013] [Revised: 07/02/2013] [Accepted: 07/04/2013] [Indexed: 12/26/2022]
Abstract
Stem cells possess huge importance in developmental biology, disease modelling, cell replacement therapy, and tissue engineering in regenerative medicine because they have the remarkable potential for self-renewal and to differentiate into almost all the cell types in the human body. Elucidation of molecular mechanisms regulating stem cell potency and differentiation is essential and critical for extensive application. Heterogeneous nuclear ribonucleoproteins (hnRNPs) are modular proteins consisting of RNA-binding motifs and auxiliary domains characterized by extensive and divergent functions in nucleic acid metabolism. Multiple roles of hnRNPs in transcriptional and posttranscriptional regulation enable them to be effective gene expression regulators. More recent findings show that hnRNP proteins are crucial factors implicated in maintenance of stem cell self-renewal and pluripotency and cell differentiation. The hnRNPs interact with certain sequences in target gene promoter regions to initiate transcription. In addition, they recognize 3′UTR or 5′UTR of specific gene mRNA forming mRNP complex to regulate mRNA stability and translation. Both of these regulatory pathways lead to modulation of gene expression that is associated with stem cell proliferation, cell cycle control, pluripotency, and committed differentiation.
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12
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Monument MJ, Bernthal NM, Randall RL. Salient features of mesenchymal stem cells-implications for Ewing sarcoma modeling. Front Oncol 2013; 3:24. [PMID: 23443465 PMCID: PMC3580960 DOI: 10.3389/fonc.2013.00024] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2013] [Accepted: 01/30/2013] [Indexed: 12/19/2022] Open
Abstract
Despite a heightened appreciation of the many defining molecular aberrations in Ewing sarcoma, the cooperative genetic environment and permissive cell of origin essential for EWS/ETS-mediated oncogenesis remain elusive. Consequently, inducible animal and in vitro models of Ewing sarcoma from a native cellular context are unable to fully recapitulate malignant transformation. Despite these shortcomings, human, and murine mesenchymal stem cells (MSCs) are the closest working in vitro systems available. MSCs are tolerant of ectopic EWS/FLI expression, which is accompanied by a molecular signature most similar to Ewing sarcoma. Whether MSCs are the elusive cell of origin or simply a tolerant platform of the EWS/FLI transcriptome, these cells have become an excellent molecular tool to investigate and manipulate oncogenesis in Ewing sarcoma. Our understanding of the biological complexity and heterogeneity of human MSCs (hMSCs) has increased substantially over time and as such, appreciation and utilization of these salient complexities may greatly enhance the efficient use of these cells as surrogate models for Ewing sarcoma tumorigenesis.
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Affiliation(s)
- Michael J Monument
- Sarcoma Services, Department of Orthopaedic Surgery, Huntsman Cancer Institute, University of Utah Salt Lake City, UT, USA
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Hamilton G, Olszewski-Hamilton U. CD99/MIC2 Constitutes a Differentiation Antigen of a Human Osteoblast Cell Line. World J Oncol 2011; 2:298-304. [PMID: 29147265 PMCID: PMC5649714 DOI: 10.4021/wjon415w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/10/2011] [Indexed: 11/03/2022] Open
Abstract
BACKGROUND The histological origin of the Ewing's family of tumors (EFT) is still not clear. Since these small cell bone tumors may originate from osteogenic stem cells, the presence of the CD99/MIC2 antigen, known to be overexpressed in EFT, was studied in a human osteoblast cell line in response to differentiation inducers. METHODS The HBA-71 monoclonal antibody directed to the CD99/MIC2 antigen was used to stain a human osteoblast cell line as well as the two EFT cell lines KAL and EW-2 after pretreatment of the cells with the differentiation inducers calcitriol and the histone deacetylase (HDAC) inhibitors sodium butyrate (NaB), sodium phenylacetate (NaPA) as well as N, N'-hexamethylen-bis-acetamide (HMBA). Alkaline phosphatase (ALP) levels were determined as cellular differentiation marker. RESULTS Significant expression of the CD99/MIC2 antigen, yielding a molecular weight of 32 kD in Western blotting, was found in the human osteoblast cell line. Pretreatment of the osteoblasts with calcitriol and HMBA increased ALP content and suppressed the CD99/MIC2 antigen. Calcitriol had no major effect on CD99/MIC2 expression of both EFT cell lines, but HMBA enhanced ALP activity in KAL cells and downregulated CD99/MIC2. EW-2 cells exhibited reduced levels of both CD99/MIC2 and ALP. CONCLUSIONS This study supports the role of CD99/MIC2 as differentiation antigen of osteoblasts and a Ewing's sarcoma cell line with neuroectodermal phenotype. Response to calcitriol is absent or low in the two EFT cell lines tested.
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Affiliation(s)
- Gerhard Hamilton
- Ludwig Boltzmann Cluster of Translational Oncology, Nussdorferstrasse 64/6, A-1090 Vienna, Austria
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Lessnick SL, Ladanyi M. Molecular pathogenesis of Ewing sarcoma: new therapeutic and transcriptional targets. ANNUAL REVIEW OF PATHOLOGY 2011; 7:145-59. [PMID: 21942527 PMCID: PMC3555146 DOI: 10.1146/annurev-pathol-011110-130237] [Citation(s) in RCA: 136] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Approximately one-third of sarcomas contain specific translocations. Ewing sarcoma is the prototypical member of this group of sarcomas; it was the first to be recognized pathologically as a singular entity and to have its signature translocation defined cytogenetically, which led to the identification of its key driver alteration, the EWS-FLI1 gene fusion that encodes this aberrant, chimeric transcription factor. We review recent progress in selected areas of Ewing sarcoma research, including the application of genome-wide chromatin immunoprecipitation analyses, to provide a comprehensive view of the EWS-FLI1 target gene repertoire, the identification of EWS-FLI1 target genes that may also point to therapeutically targetable pathways, and data from model systems as they relate to the elusive cell of origin of Ewing sarcoma and its possible similarities to mesenchymal stem cells.
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Affiliation(s)
- Stephen L. Lessnick
- Center for Children's Cancer Research at Huntsman Cancer Institute, Department of Oncological Sciences, and Division of Pediatric Hematology and Oncology, University of Utah School of Medicine, Salt Lake City, Utah 84112;
| | - Marc Ladanyi
- Molecular Diagnostics Service, Department of Pathology, and Human Oncology and Pathogenesis Program, Memorial Sloan-Kettering Cancer Center, New York, New York 10065;
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Grohar PJ, Woldemichael GM, Griffin LB, Mendoza A, Chen QR, Yeung C, Currier DG, Davis S, Khanna C, Khan J, McMahon JB, Helman LJ. Identification of an inhibitor of the EWS-FLI1 oncogenic transcription factor by high-throughput screening. J Natl Cancer Inst 2011; 103:962-78. [PMID: 21653923 DOI: 10.1093/jnci/djr156] [Citation(s) in RCA: 150] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
BACKGROUND Chromosomal translocations generating oncogenic transcription factors are the hallmark of a variety of tumors, including many sarcomas. Ewing sarcoma family of tumors (ESFTs) are characterized by the t(11;22)(q24;q12) translocation that generates the Ewing sarcoma breakpoint region 1 and Friend leukemia virus integration 1 (EWS-FLI1) fusion transcription factor responsible for the highly malignant phenotype of this tumor. Although continued expression of EWS-FLI1 is believed to be critical for ESFT cell survival, a clinically effective small-molecule inhibitor remains elusive likely because EWS-FLI1 is a transcription factor and therefore widely felt to be "undruggable." METHODS We developed a high-throughput screen to evaluate more than 50 000 compounds for inhibition of EWS-FLI1 activity in TC32 ESFT cells. We used a TC32 cell-based luciferase reporter screen using the EWS-FLI1 downstream target NR0B1 promoter and a gene signature secondary screen to sort and prioritize the compounds. We characterized the lead compound, mithramycin, based on its ability to inhibit EWS-FLI1 activity in vitro using microarray expression profiling, quantitative reverse transcription-polymerase chain reaction, and immunoblot analysis, and in vivo using immunohistochemistry. We studied the impact of this inhibition on cell viability in vitro and on tumor growth in ESFT xenograft models in vivo (n = 15-20 mice per group). All statistical tests were two-sided. RESULTS Mithramycin inhibited expression of EWS-FLI1 downstream targets at the mRNA and protein levels and decreased the growth of ESFT cells at half maximal inhibitory concentrations between 10 (95% confidence interval [CI] = 8 to 13 nM) and 15 nM (95% CI = 13 to 19 nM). Mithramycin suppressed the growth of two different ESFT xenograft tumors and prolonged the survival of ESFT xenograft-bearing mice by causing a decrease in mean tumor volume. For example, in the TC32 xenograft model, on day 15 of treatment, the mean tumor volume for the mithramycin-treated mice was approximately 3% of the tumor volume observed in the control mice (mithramycin vs control: 69 vs 2388 mm(3), difference = 2319 mm(3), 95% CI = 1766 to 2872 mm(3), P < .001). CONCLUSION Mithramycin inhibits EWS-FLI1 activity and demonstrates ESFT antitumor activity both in vitro and in vivo.
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Affiliation(s)
- Patrick J Grohar
- Molecular Oncology Section, Pediatric Oncology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, 10 Center Dr-MSC 1104, 10 CRC 1W-3816, Bethesda, MD 20892-1104, USA.
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16
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Lin HY, Lin YJ. In vitro effects of low frequency electromagnetic fields on osteoblast proliferation and maturation in an inflammatory environment. Bioelectromagnetics 2011; 32:552-60. [PMID: 21448989 DOI: 10.1002/bem.20668] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2010] [Accepted: 03/01/2011] [Indexed: 11/06/2022]
Abstract
An in vitro model was set up to investigate the effects of low frequency pulsed electromagnetic fields (PEMF) and its induced electric fields on osteoblast cells under inflammatory conditions. Osteoblasts (7F2) were seeded on top of chitosan scaffolds and co-cultured with macrophage cells (RAW 264.7) growing on the bottom of culture wells, stimulated by lipopolysaccharide to release reactive oxygen species including nitric oxide (NO). The co-culture was exposed to PEMF (magnitude of the magnetic field = 1.5 mT; induced electric voltage = 2.5 mV; frequency = 75 Hz; pulse duration = 1.3 ms) for 9 h. The osteoblasts were examined for their proliferation, viability, alkaline phosphatase (ALP) activity, and genetic expressions of type I collagen (COL I) and osteocalcin (OC), immediately and 7 days after PEMF exposure (days 0 and 7). Macrophage cell viability and NO concentration in the medium were monitored before and after PEMF exposure. The PEMF-exposed co-culture released a significantly higher amount of NO (65 µM) compared to control (17 µM) on day 7. Despite the high level of NO in the medium that was reported to be cytotoxic, PEMF-exposed osteoblasts had enhanced cell proliferation (23%), viability (36%), and COL I mRNA expression (3.4-fold) compared to the controls. The osteoblasts subjected to the PEMF had 41% less ALP activity than the control, which was associated with the active cell proliferation and COL I expression. The expression of OC mRNA was not seen in either the PEMF or control group, indicating cells had not entered the mineralization stage by day 7.
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Affiliation(s)
- Hsin-Yi Lin
- Department of Chemical Engineering and Biotechnology, National Taipei University of Technology, Taipei, Taiwan.
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Li X, McGee-Lawrence ME, Decker M, Westendorf JJ. The Ewing's sarcoma fusion protein, EWS-FLI, binds Runx2 and blocks osteoblast differentiation. J Cell Biochem 2011; 111:933-43. [PMID: 20665663 DOI: 10.1002/jcb.22782] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Ewing's sarcomas are highly aggressive round cell tumors of bone and soft tissues that afflict children and young adults. The majority of these tumors harbor the t(11;22) translocation and express the fusion protein EWS-FLI. Modern molecular profiling experiments indicate that Ewing's tumors originate from mesenchymal precursors in young individuals. EWS-FLI alters the morphology of mesenchymal cells and prevents lineage specification; however, the molecular mechanisms for differentiation arrest are unclear. We recently showed that EWS-FLI binds Runx2, a master regulator of osteoblast differentiation. In this report, we demonstrate that FLI sequences within EWS-FLI are responsible for interactions with Runx2. EWS-FLI blocks the expression of osteoblastic genes in a multipotent progenitor cell line that requires Runx2 to integrate bone morphogenic protein (Bmp)2 signaling while increasing proliferation and altering cell morphology. These results demonstrate that EWS-FLI blocks the ability of Runx2 to induce osteoblast specification of a mesenchymal progenitor cell. Disrupting interactions between Runx2 and EWS-FLI1 may promote differentiation of the tumor cell.
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Affiliation(s)
- Xiaodong Li
- Mayo Clinic, Rochester, Minnesota 55905, USA
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18
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EWS/ETS proteins promote expression and regulate function of the homeodomain transcription factor BRN3A. Oncogene 2010; 29:3134-45. [PMID: 20348952 DOI: 10.1038/onc.2010.72] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Ewing's sarcoma family tumors (ESFTs or EFTs) express neuronal markers, which indicates they may originate from cells at least partly committed to neuronal lineage. However, recent publications suggest EFT originates in mesenchymal stem cells, and EWS/ETS fusion proteins characteristic of EFT activate neuronal marker expression to confer a neural phenotype on EFT. Here we show that the neuronal marker BRN3A/POU4F1 is expressed abundantly at the protein level in primary EFT but not in rhabdomyosarcoma and neuroblastoma, and EFT cells exhibit high activity of the BRN3A proximal autoregulatory region. EWS/FLI-1 siRNA reduces BRN3A expression and promoter activity and EWS/ETS proteins are bound to the BRN3A locus, suggesting a direct function for EWS/ETS proteins in control of BRN3A expression. Differentiation-associated and autoregulatory activities of BRN3A are respectively impaired and altered in EFT cells, and EWS/FLI-1 siRNA can restore some BRN3A function. A potentially novel function for BRN3A in EFT cells is identified. These results extend the hypothesis that EWS/ETS proteins induce expression of neuronal markers such as BRN3A in EFT by showing that the function of those same markers may be restricted or controlled in an EWS/ETS-dependent manner.
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Luther G, Rames R, Wagner ER, Zhu G, Luo Q, Bi Y, Kim SH, Gao JL, Huang E, Yang K, Wang L, Liu X, Li M, Hu N, Su Y, Luo X, Chen L, Luo J, Haydon RC, Luu HH, Zhou L, He TC. Molecular basis of differentiation therapy for soft tissue sarcomas. TRENDS IN CANCER RESEARCH 2010; 6:69-90. [PMID: 26912947 PMCID: PMC4762605] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Stem cells are undifferentiated precursor cells with the capacity for proliferation or terminal differentiation. Progression down the differentiation cascade results in a loss of proliferative potential in exchange for the differentiated phenotype. This balance is tightly regulated in the physiologic state. Recent studies, however, have demonstrated that during tumorigenesis, disruptions preventing terminal differentiation allow cancer cells to maintain a proliferative, precursor cell phenotype. Current therapies (i.e., chemotherapy and radiation therapy) target the actively proliferating cells in tumor masses, which in many cases inevitably induce therapy-resistant cancer cells. It is conceivable that promising therapy regimens can be developed by treating human cancers by inducing terminal differentiation, thereby restoring the interrupted pathway and shifting the balance from proliferation to differentiation. For example, osteosarcoma (OS) is a primary bone cancer caused by differentiation defects in mesenchymal stem cells (MSCs) for which several differentiation therapies have shown great promise. In this review, we discuss the various differentiation therapies in the treatment of human sarcomas with a focus on OS. Such therapies hold great promise as they not only inhibit tumorigenesis, but also avoid the adverse effects associated with conventional chemotherapy regimens. Furthermore, it is conceivable that a combination of conventional therapies with differentiation therapy should significantly improve anticancer efficacy and reduce drug-resistance in the clinical management of human cancers, including sarcomas.
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Affiliation(s)
- Gaurav Luther
- Molecular Oncology Laboratory, Department of Surgery, The University of Chicago Medical Center, Chicago, IL 60637, USA
| | - Richard Rames
- Molecular Oncology Laboratory, Department of Surgery, The University of Chicago Medical Center, Chicago, IL 60637, USA
| | - Eric R. Wagner
- Molecular Oncology Laboratory, Department of Surgery, The University of Chicago Medical Center, Chicago, IL 60637, USA
| | - Gaohui Zhu
- Molecular Oncology Laboratory, Department of Surgery, The University of Chicago Medical Center, Chicago, IL 60637, USA
- Stem Cell Biology and Therapy Laboratory, The Children's Hospital of Chongqing Medical University, Chongqing 400014, China
| | - Qing Luo
- Molecular Oncology Laboratory, Department of Surgery, The University of Chicago Medical Center, Chicago, IL 60637, USA
- Stem Cell Biology and Therapy Laboratory, The Children's Hospital of Chongqing Medical University, Chongqing 400014, China
| | - Yang Bi
- Molecular Oncology Laboratory, Department of Surgery, The University of Chicago Medical Center, Chicago, IL 60637, USA
- Stem Cell Biology and Therapy Laboratory, The Children's Hospital of Chongqing Medical University, Chongqing 400014, China
| | - Stephanie H. Kim
- Molecular Oncology Laboratory, Department of Surgery, The University of Chicago Medical Center, Chicago, IL 60637, USA
| | - Jian-Li Gao
- Molecular Oncology Laboratory, Department of Surgery, The University of Chicago Medical Center, Chicago, IL 60637, USA
- Key Laboratory of Diagnostic Medicine designated by Chinese Ministry of Education and Affiliated Hospitals, Chongqing Medical University, Chongqing 400016, China
| | - Enyi Huang
- Molecular Oncology Laboratory, Department of Surgery, The University of Chicago Medical Center, Chicago, IL 60637, USA
- School of Bioengineering, Chongqing University, Chongqing 400044, China
| | - Ke Yang
- Molecular Oncology Laboratory, Department of Surgery, The University of Chicago Medical Center, Chicago, IL 60637, USA
- Department of Cell Biology, The Third Military Medical University, Chongqing 400030, China
| | - Linyuan Wang
- Molecular Oncology Laboratory, Department of Surgery, The University of Chicago Medical Center, Chicago, IL 60637, USA
| | - Xing Liu
- Molecular Oncology Laboratory, Department of Surgery, The University of Chicago Medical Center, Chicago, IL 60637, USA
- Stem Cell Biology and Therapy Laboratory, The Children's Hospital of Chongqing Medical University, Chongqing 400014, China
| | - Mi Li
- Molecular Oncology Laboratory, Department of Surgery, The University of Chicago Medical Center, Chicago, IL 60637, USA
- Stem Cell Biology and Therapy Laboratory, The Children's Hospital of Chongqing Medical University, Chongqing 400014, China
| | - Ning Hu
- Molecular Oncology Laboratory, Department of Surgery, The University of Chicago Medical Center, Chicago, IL 60637, USA
- Key Laboratory of Diagnostic Medicine designated by Chinese Ministry of Education and Affiliated Hospitals, Chongqing Medical University, Chongqing 400016, China
| | - Yuxi Su
- Molecular Oncology Laboratory, Department of Surgery, The University of Chicago Medical Center, Chicago, IL 60637, USA
- Stem Cell Biology and Therapy Laboratory, The Children's Hospital of Chongqing Medical University, Chongqing 400014, China
| | - Xiaoji Luo
- Molecular Oncology Laboratory, Department of Surgery, The University of Chicago Medical Center, Chicago, IL 60637, USA
- Key Laboratory of Diagnostic Medicine designated by Chinese Ministry of Education and Affiliated Hospitals, Chongqing Medical University, Chongqing 400016, China
| | - Liang Chen
- Molecular Oncology Laboratory, Department of Surgery, The University of Chicago Medical Center, Chicago, IL 60637, USA
- Key Laboratory of Diagnostic Medicine designated by Chinese Ministry of Education and Affiliated Hospitals, Chongqing Medical University, Chongqing 400016, China
| | - Jinyong Luo
- Molecular Oncology Laboratory, Department of Surgery, The University of Chicago Medical Center, Chicago, IL 60637, USA
- Key Laboratory of Diagnostic Medicine designated by Chinese Ministry of Education and Affiliated Hospitals, Chongqing Medical University, Chongqing 400016, China
| | - Rex C. Haydon
- Molecular Oncology Laboratory, Department of Surgery, The University of Chicago Medical Center, Chicago, IL 60637, USA
| | - Hue H. Luu
- Molecular Oncology Laboratory, Department of Surgery, The University of Chicago Medical Center, Chicago, IL 60637, USA
| | - Lan Zhou
- Molecular Oncology Laboratory, Department of Surgery, The University of Chicago Medical Center, Chicago, IL 60637, USA
- Key Laboratory of Diagnostic Medicine designated by Chinese Ministry of Education and Affiliated Hospitals, Chongqing Medical University, Chongqing 400016, China
| | - Tong-Chuan He
- Molecular Oncology Laboratory, Department of Surgery, The University of Chicago Medical Center, Chicago, IL 60637, USA
- Stem Cell Biology and Therapy Laboratory, The Children's Hospital of Chongqing Medical University, Chongqing 400014, China
- Key Laboratory of Diagnostic Medicine designated by Chinese Ministry of Education and Affiliated Hospitals, Chongqing Medical University, Chongqing 400016, China
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Abstract
Ewing's sarcoma/PNET are small round cell tumors showing a varying degree of neuroectodermal differentiation. They are one of the commonest tumors of childhood and occur in bone and within soft tissues. Traditionally, light microscopy with the aid of immunohistochemical stains was suitable for diagnosis. But now translocation analyses are being used not only for the diagnosis and classification of small round cell tumors, but to ascertain their prognostic significance, detect micrometastasis, and monitor minimal residual disease, with potential for targeted therapy. This article analyzes the pathology, biology, and molecular aspects of Ewing's sarcoma/PNET and discusses their clinical and therapeutic implications.
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Affiliation(s)
- Saral S Desai
- Department of Pathology, Tata Memorial Hospital, Dr. Ernest Borges Road, Parel, Mumbai, Maharashtra, India
| | - Nirmala A Jambhekar
- Department of Pathology, Tata Memorial Hospital, Dr. Ernest Borges Road, Parel, Mumbai, Maharashtra, India,Address for correspondence: Dr. Nirmala Jambhekar, Department of Pathology, Tata Memorial Hospital, Parel, Mumbai-400 012, Maharashtra, India. E-mail:
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Abstract
Ewing sarcoma accounts for about 2% to 3% of childhood tumors and can occur in any bone, but it is most often found in extremities and central axis. Ewing sarcoma affecting clavicle is uncommon. We report 5 cases of Ewing sarcoma of clavicle treated in our institution. The mean age at the time of diagnosis was 11.6 years (2 to 15 y). There were 3 males and 2 females. All patients received chemotherapy before and after the surgery. Likewise, radiotherapy was administrated after tumor excision in one patient. Different methods of surgical treatment were used and included: claviculectomy, claviculectomy and vascularized fibular autograft, and claviculectomy and clavicle allograft. One patient died during the follow-up because of the recurrence of the tumor and presence of metastatic disease. The remaining 4 patients had good functional outcomes with no pain of the shoulder at final follow-up. In conclusion, Ewing sarcoma of clavicle is a very rare tumor and different methods of surgical treatment can be used. Clavicle often can be resected with no need for reconstruction, especially in young children. Autografts or allografts can restore the normal anatomy of the shoulder.
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Tan AY, Manley JL. The TET family of proteins: functions and roles in disease. J Mol Cell Biol 2009; 1:82-92. [PMID: 19783543 DOI: 10.1093/jmcb/mjp025] [Citation(s) in RCA: 204] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Translocated in liposarcoma, Ewing's sarcoma and TATA-binding protein-associated factor 15 constitute an interesting and important family of proteins known as the TET proteins. The proteins function in several aspects of cell growth control, including multiple different steps in gene expression, and they are also found mutated in a number of specific diseases. For example, all contain domains for binding nucleic acids and have been shown to function in both RNA polymerase II-mediated transcription and pre-mRNA splicing, possibly connecting these two processes. Chromosomal translocations in human sarcomas result in a fusion of the amino terminus of these proteins, which contains a transcription activation domain, to the DNA-binding domain of a transcription factor. Although the fusion proteins have been characterized in a clinical environment, the function of the cognate full-length protein in normal cells is a more recent topic of study. The first part of this review will describe the TET proteins, followed by detailed descriptions of their multiple roles in cells. The final sections will examine changes that occur in gene regulation in cells expressing the fusion proteins. The clinical implications and treatment of sarcomas will not be addressed but have recently been reviewed.
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Affiliation(s)
- Adelene Y Tan
- Department of Biological Sciences, Columbia University, New York, NY 10027, USA
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Lin PP, Pandey MK, Jin F, Xiong S, Deavers M, Parant JM, Lozano G. EWS-FLI1 induces developmental abnormalities and accelerates sarcoma formation in a transgenic mouse model. Cancer Res 2008; 68:8968-75. [PMID: 18974141 DOI: 10.1158/0008-5472.can-08-0573] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Ewing's sarcoma is characterized by the t(11;22)(q24:q12) reciprocal translocation. To study the effects of the fusion gene EWS-FLI1 on development and tumor formation, a transgenic mouse model was created. A strategy of conditional expression was used to limit the potentially deleterious effects of EWS-FLI1 to certain tissues. In the absence of Cre recombinase, EWS-FLI1 was not expressed in the EWS-FLI1 transgenic mice, and they had a normal phenotype. When crossed to the Prx1-Cre transgenic mouse, which expresses Cre recombinase in the primitive mesenchymal cells of the embryonic limb bud, the EF mice were noted to have a number of developmental defects of the limbs. These included shortening of the limbs, muscle atrophy, cartilage dysplasia, and immature bone. By itself, EWS-FLI1 did not induce the formation of tumors in the EF transgenic mice. However, in the setting of p53 deletion, EWS-FLI1 accelerated the formation of sarcomas from a median time of 50 to 21 weeks. Furthermore, EWS-FLI1 altered the type of tumor that formed. Conditional deletion of p53 in mesenchymal cells (Prx1-Cre p53(lox/lox)) produced osteosarcomas as the predominant tumor. The presence of EWS-FLI1 shifted the tumor phenotype to a poorly differentiated sarcoma. The results taken together suggest that EWS-FLI1 inhibits normal limb development and accelerates the formation of poorly differentiated sarcomas.
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Affiliation(s)
- Patrick P Lin
- Department of Orthopaedic Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA.
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25
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Liu S, Cheng H, Kwan W, Lubieniecka JM, Nielsen TO. Histone deacetylase inhibitors induce growth arrest, apoptosis, and differentiation in clear cell sarcoma models. Mol Cancer Ther 2008; 7:1751-61. [PMID: 18566246 DOI: 10.1158/1535-7163.mct-07-0560] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Clear cell sarcoma is an aggressive malignancy occurring most commonly in the distal extremities of young adults, characterized by t(12;22)(q13;q12) creating the chimeric fusion oncoprotein EWS-ATF1. We assessed growth inhibition and differentiation effects of histone deacetylase inhibitors MS-275 and romidepsin (depsipeptide, FK228) on clear cell sarcoma cells and evaluated drug sensitivity among related translocation-associated sarcomas and other cell models. Three clear cell sarcoma cell lines, seven other sarcomas, six nonsarcoma malignant cell lines, and two nonneoplastic mesenchymal cell models were treated with MS-275 or romidepsin. Growth inhibition was assayed by monolayer 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Induction of cell cycle arrest and apoptosis were assessed by propidium iodide/Annexin V flow cytometry in monolayer and spheroid cultures and by immunoblotting analysis. Expression levels of key genes involved in mesenchymal differentiation and of EWS-ATF1 were measured by quantitative real-time PCR in clear cell sarcoma cells treated with histone deacetylase inhibitors. MS-275 and romidepsin inhibited growth in clear cell sarcoma cells by inducing cell cycle arrest and apoptosis in a time- and dose-dependent manner. Sarcomas showed greater sensitivity than other tumor types, with clear cell sarcomas most sensitive of all, whereas nonmalignant mesenchymal cells were highly resistant. MS-275 at 1 micromol/L and romidepsin at 1 nmol/L induced histone H3 acetylation, cell cycle arrest, apoptosis, and differentiation in clear cell sarcoma cells within 24 hours. Histone deacetylase inhibitors increased expression of SOX9, MYOD1, and PPARG and decreased EWS-ATF1 expression in clear cell sarcoma cells. Histone deacetylase inhibitors show promising preclinical activity in multiple clear cell sarcoma models.
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Affiliation(s)
- Shuzhen Liu
- Genetic Pathology Evaluation Centre, University of British Columbia, Vancouver, British Columbia, Canada
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26
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Neural differentiation arrest in embryonal carcinoma cells with forced expression of EWS-FLI1. J Neurooncol 2008; 90:141-50. [DOI: 10.1007/s11060-008-9646-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2008] [Accepted: 06/20/2008] [Indexed: 11/25/2022]
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Schlaak M, Renner R, Treudler R, Harth W, Poenisch W, Kauer F, Grunewald S, Wittekind C, Simon JC. CD30+ anaplastic lymphoma kinase-positive anaplastic large cell lymphoma with an unusual translocation t(11;22). Br J Dermatol 2008; 159:240-2. [PMID: 18489597 DOI: 10.1111/j.1365-2133.2008.08602.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: 11/27/2022]
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28
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Delattre O. [Ewing's tumours, genetic and cellular aspects]. ACTA ACUST UNITED AC 2008; 56:257-9. [PMID: 18485618 DOI: 10.1016/j.patbio.2008.03.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2008] [Accepted: 03/14/2008] [Indexed: 11/26/2022]
Abstract
Ewing's tumour is the second most frequent primary tumour of bone. It is associated in 85% of cases with a specific and recurrent chromosome translocation, a t(11; 22)(q24; q12) which generates a fusion gene between the 5' part of EWS and the 3' part of FLI-1, a member of the ETS family. Less frequently, this gene fusion involves EWS and another member of the ETS family which can be: ERG, ETV1, E1AF or FEV depending on the cases. The EWS-ETS fusion is causative in the development of Ewing's tumour. Its mechanism of action mainly relies on the abnormal transcription regulation of key target genes which are involved in the regulation of cell cycle, signal transduction, migration. The cellular context within which EWS-FLI-1 exerts its oncogenic action is a long standing matter of debate. Recent data converge to suggest that the Ewing cell origin is a mesenchymal stem cell.
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Riggi N, Suvà ML, Suvà D, Cironi L, Provero P, Tercier S, Joseph JM, Stehle JC, Baumer K, Kindler V, Stamenkovic I. EWS-FLI-1 expression triggers a Ewing's sarcoma initiation program in primary human mesenchymal stem cells. Cancer Res 2008; 68:2176-85. [PMID: 18381423 DOI: 10.1158/0008-5472.can-07-1761] [Citation(s) in RCA: 243] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Ewing's sarcoma family tumors (ESFT) express the EWS-FLI-1 fusion gene generated by the chromosomal translocation t(11;22)(q24;q12). Expression of the EWS-FLI-1 fusion protein in a permissive cellular environment is believed to play a key role in ESFT pathogenesis. However, EWS-FLI-1 induces growth arrest or apoptosis in differentiated primary cells, and the identity of permissive primary human cells that can support its expression and function has until now remained elusive. Here we show that expression of EWS-FLI-1 in human mesenchymal stem cells (hMSC) is not only stably maintained without inhibiting proliferation but also induces a gene expression profile bearing striking similarity to that of ESFT, including genes that are among the highest ESFT discriminators. Expression of EWS-FLI-1 in hMSCs may recapitulate the initial steps of Ewing's sarcoma development, allowing identification of genes that play an important role early in its pathogenesis. Among relevant candidate transcripts induced by EWS-FLI-1 in hMSCs, we found the polycomb group gene EZH2, which we show to play a critical role in Ewing's sarcoma growth. These observations are consistent with our recent findings using mouse mesenchymal progenitor cells and provide compelling evidence that hMSCs are candidate cells of origin of ESFT.
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Affiliation(s)
- Nicolò Riggi
- Division of Experimental Pathology, Institute of Pathology, University of Lausanne, Switzerland
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Luan Y, Yu XP, Yang N, Frenkel S, Chen L, Liu CJ. p204 protein overcomes the inhibition of core binding factor alpha-1-mediated osteogenic differentiation by Id helix-loop-helix proteins. Mol Biol Cell 2008; 19:2113-26. [PMID: 18287524 DOI: 10.1091/mbc.e07-10-1057] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Id proteins play important roles in osteogenic differentiation; however, the molecular mechanism remains unknown. In this study, we established that inhibitor of differentiation (Id) proteins, including Id1, Id2, and Id3, associate with core binding factor alpha-1 (Cbfa1) to cause diminished transcription of the alkaline phosphatase (ALP) and osteocalcin (OCL) gene, leading to less ALP activity and osteocalcin (OCL) production. Id acts by inhibiting the sequence-specific binding of Cbfa1 to DNA and by decreasing the expression of Cbfa1 in cells undergoing osteogenic differentiation. p204, an interferon-inducible protein that interacts with both Cbfa1 and Id2, overcame the Id2-mediated inhibition of Cbfa1-induced ALP activity and OCL production. We show that 1) p204 disturbed the binding of Id2 to Cbfa1 and enabled Cbfa1 to bind to the promoters of its target genes and 2) that p204 promoted the translocation from nucleus to the cytoplasm and accelerated the degradation of Id2 by ubiquitin-proteasome pathway during osteogenesis. Nucleus export signal (NES) of p204 is required for the p204-enhanced cytoplasmic translocation and degradation of Id2, because a p204 mutant lacking NES lost these activities. Together, Cbfa1, p204, and Id proteins form a regulatory circuit and act in concert to regulate osteoblast differentiation.
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Affiliation(s)
- Yi Luan
- Department of Orthopaedic Surgery, New York University School of Medicine, New York, NY 10003, USA
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Inducible expression of chimeric EWS/ETS proteins confers Ewing's family tumor-like phenotypes to human mesenchymal progenitor cells. Mol Cell Biol 2008; 28:2125-37. [PMID: 18212050 DOI: 10.1128/mcb.00740-07] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Ewing's family tumor (EFT) is a rare pediatric tumor of unclear origin that occurs in bone and soft tissue. Specific chromosomal translocations found in EFT cause EWS to fuse to a subset of ets transcription factor genes (ETS), generating chimeric EWS/ETS proteins. These proteins are believed to play a crucial role in the onset and progression of EFT. However, the mechanisms responsible for the EWS/ETS-mediated onset remain unclear. Here we report the establishment of a tetracycline-controlled EWS/ETS-inducible system in human bone marrow-derived mesenchymal progenitor cells (MPCs). Ectopic expression of both EWS/FLI1 and EWS/ERG proteins resulted in a dramatic change of morphology, i.e., from a mesenchymal spindle shape to a small round-to-polygonal cell, one of the characteristics of EFT. EWS/ETS also induced immunophenotypic changes in MPCs, including the disappearance of the mesenchyme-positive markers CD10 and CD13 and the up-regulation of the EFT-positive markers CD54, CD99, CD117, and CD271. Furthermore, a prominent shift from the gene expression profile of MPCs to that of EFT was observed in the presence of EWS/ETS. Together with the observation that EWS/ETS enhances the ability of cells to invade Matrigel, these results suggest that EWS/ETS proteins contribute to alterations of cellular features and confer an EFT-like phenotype to human MPCs.
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32
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Tirode F, Laud-Duval K, Prieur A, Delorme B, Charbord P, Delattre O. Mesenchymal stem cell features of Ewing tumors. Cancer Cell 2007; 11:421-9. [PMID: 17482132 DOI: 10.1016/j.ccr.2007.02.027] [Citation(s) in RCA: 378] [Impact Index Per Article: 22.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2006] [Revised: 12/04/2006] [Accepted: 02/28/2007] [Indexed: 12/12/2022]
Abstract
The cellular origin of Ewing tumor (ET), a tumor of bone or soft tissues characterized by specific fusions between EWS and ETS genes, is highly debated. Through gene expression analysis comparing ETs with a variety of normal tissues, we show that the profiles of different EWS-FLI1-silenced Ewing cell lines converge toward that of mesenchymal stem cells (MSC). Moreover, upon EWS-FLI1 silencing, two different Ewing cell lines can differentiate along the adipogenic lineage when incubated in appropriate differentiation cocktails. In addition, Ewing cells can also differentiate along the osteogenic lineage upon long-term inhibition of EWS-FLI1. These in silico and experimental data strongly suggest that the inhibition of EWS-FLI1 may allow Ewing cells to recover the phenotype of their MSC progenitor.
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Affiliation(s)
- Franck Tirode
- Institut Curie, 26 rue d'Ulm, 75248 Paris cedex 05, France
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33
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González I, Vicent S, de Alava E, Lecanda F. EWS/FLI-1 oncoprotein subtypes impose different requirements for transformation and metastatic activity in a murine model. J Mol Med (Berl) 2007; 85:1015-29. [PMID: 17453169 DOI: 10.1007/s00109-007-0202-5] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2006] [Revised: 03/15/2007] [Accepted: 03/26/2007] [Indexed: 12/20/2022]
Abstract
Ewing sarcoma/primitive neuroectodermal tumors (EWS/PNET) are characterized by specific chromosomal translocations most often generating a chimeric EWS/FLI-1 gene. Depending on the number of juxtaposed exons assembled, several fusion types have been described with different incidences and prognoses. To assess the impact of each fusion type on the specific phenotypic, tumorigenic, and metastatic features of EWS/PNET, we developed an amenable system using a murine mesenchymal multipotent C3H10T1/2 cell line. Upon transduction of EWS/FLI-1, cells acquired dramatic morphological changes in vitro, including a smaller size and "neurite-like" membrane elongations. Chimeric fusion proteins conferred oncogenic properties in vitro, including anchorage-independent growth and an increased rate of proliferation. Furthermore, EWS/FLI-1 expression blocked mineralization, with concomitant repression of osteoblastic genes, and induced a dramatic repression of the adipocytic differentiation program. Moreover, EWS/FLI-1 promoted an aberrant neural phenotype by the de novo expression of specific neural genes. The intramuscular injection of transduced cells led to tumor development and the induction of overt osteolytic lesions. Analogously, to what was observed in human tumors, type 2 EWS/FLI-1 cells formed primary tumors in immunodeficient mice with a higher incidence and a lower latency than cells bearing types 1 and 3 fusions. By contrast, cells expressing types 2 and 3 fusions showed specific metastatic activity with a higher number of macroscopic metastases in soft tissues and osteolytic lesions in the limbs as compared to type-1-expressing cells. Therefore, the structure of each oncoprotein strongly influenced its tumorigenicity and metastagenicity. Thus, this model provides a basis for understanding the genetic determinants involved in Ewing tumor development and metastatic activity and represents a cellular system to analyze other oncoproteins involved in human sarcomagenesis.
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MESH Headings
- Animals
- Blotting, Western
- Cell Line
- Cell Line, Tumor
- Cell Proliferation
- Cell Transformation, Neoplastic/genetics
- Cell Transformation, Neoplastic/metabolism
- Female
- Flow Cytometry
- Fluorescent Antibody Technique
- Humans
- Mice
- Mice, Inbred C3H
- Mice, Nude
- Microscopy, Electron, Scanning
- Neoplasm Metastasis
- Oncogene Proteins, Fusion/genetics
- Oncogene Proteins, Fusion/metabolism
- Proto-Oncogene Protein c-fli-1/genetics
- Proto-Oncogene Protein c-fli-1/metabolism
- RNA-Binding Protein EWS
- Radiography
- Reverse Transcriptase Polymerase Chain Reaction
- Sarcoma, Ewing/diagnostic imaging
- Sarcoma, Ewing/genetics
- Sarcoma, Ewing/pathology
- Sarcoma, Experimental/diagnostic imaging
- Sarcoma, Experimental/genetics
- Sarcoma, Experimental/pathology
- Transplantation, Heterologous
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Affiliation(s)
- Iranzu González
- Division of Oncology, Adhesion and Metastasis Laboratory, Center for Applied Medical Research (CIMA), University of Navarra, Pamplona, 31080, Navarra, Spain
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34
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Luan Y, Yu XP, Xu K, Ding B, Yu J, Huang Y, Yang N, Lengyel P, Di Cesare PE, Liu CJ. The retinoblastoma protein is an essential mediator of osteogenesis that links the p204 protein to the Cbfa1 transcription factor thereby increasing its activity. J Biol Chem 2007; 282:16860-70. [PMID: 17439944 DOI: 10.1074/jbc.m610943200] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Bone formation requires the coordinated activity of numerous proteins including the transcription factor core-binding factor alpha1 (Cbfa1). Deregulation of Cbfa1 results in metabolic bone diseases including osteoporosis and osteopetrosis. The retinoblastoma protein (pRb) that is required for osteogenesis binds Cbfa1. We reported earlier that the p200 family protein p204, which is known to be involved in the differentiation of skeletal muscle myotubes, cardiac myocytes, and macrophages, also serves as a cofactor of Cbfa1 and promotes osteogenesis. In this study we established that suppression of p204 expression by an adenovirus construct encoding p204 antisense RNA inhibited osteoblast-specific gene activation by Cbfa1 in an osteogenesis assay involving the pluripotent C2C12 mesenchymal cell line. Using protein-protein interaction assays we established that Cbfa1, pRb, and p204 form a ternary complex in which pRb serves as a linker connecting p204 and Cbfa1. Chromatin immunoprecipitation assays revealed the binding of such a p204-pRb-Cbfa1 transcription factor complex to the promoter of the osteocalcin gene. The pRb requirement of the stimulation of Cbfa1 activity by p204 was established in experiments involving p204 mutants lacking one or two pRb binding (LXCXE) motifs. Such mutants failed to enhance the Cbfa1-dependent transactivation of gene expression as well as osteogenesis. Furthermore, as revealed in reporter gene and in vitro osteogenesis assays p204 synergized with pRb in the stimulation of Cbfa1-dependent gene activation and osteoblast differentiation.
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Affiliation(s)
- Yi Luan
- Department of Orthopedic Surgery, New York University Medical Center, New York, New York 10003, USA
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35
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Riggi N, Stamenkovic I. The Biology of Ewing sarcoma. Cancer Lett 2007; 254:1-10. [PMID: 17250957 DOI: 10.1016/j.canlet.2006.12.009] [Citation(s) in RCA: 195] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2006] [Revised: 12/05/2006] [Accepted: 12/12/2006] [Indexed: 12/19/2022]
Abstract
Sarcomas account for less than 10% of all human malignancies that are believed to originate from as yet poorly defined mesenchymal progenitor cells. They constitute some of the most aggressive adult and childhood cancers in that they have a high metastatic proclivity and are typically refractory to conventional chemo- and radiation therapy. Ewing's sarcoma is a member of Ewing's family tumors (ESFT) and the second most common solid bone and soft tissue malignancy of children and young adults. It is associated in 85% of cases with the t(11;22)(q24:q12) chromosomal translocation that generates fusion of the 5' segment of the EWS gene with the 3' segment of the ETS family gene FLI-1. The resulting EWS-FLI-1 fusion protein is believed to behave as an aberrant transcriptional activator that contributes to ESFT development by altering the expression of its target genes in a permissive cellular environment. Although ESFTs are among the best studied sarcomas, the mechanisms involved in EWS-FLI-1-induced transformation require further elucidation and the primary cells from which ESFTs originate need to be identified. This review will highlight some of the most recent discoveries in the field of Ewing sarcoma biology and origins.
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Affiliation(s)
- Nicolò Riggi
- Division of Experimental Pathology, Institute of Pathology, University of Lausanne, Switzerland
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36
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Fischer G, Odunsi K, Lele S, Mhawech P. Ovarian primary primitive neurectodermal tumor coexisting with endometrioid adenocarcinoma: a case report. Int J Gynecol Pathol 2006; 25:151-4. [PMID: 16633064 DOI: 10.1097/01.pgp.0000185408.31427.4e] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
We report an unusual case of a 78-year-old woman with primary ovarian tumor that consisted of primitive neurectodermal tumor and endometrioid adenocarcinoma. The patient presented with abdominal pain and weight loss and had disseminated disease at her initial presentation. She was treated with debulking surgery followed by chemotherapy. The patient was still asymptomatic at the 6-month follow-up.
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Affiliation(s)
- Gabor Fischer
- Department of Pathology, Roswell Park Cancer Institute, Buffalo, New York 14263, USA
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37
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Abstract
For decades anatomic imaging with computed tomography or magnetic resonance imaging has facilitated drug development in medical oncology by providing quantifiable and objective evidence of response to cancer therapy. In recent years metabolic imaging with [18F]fluorodeoxyglucose–positron emission tomography has added an important component to the oncologist's armamentarium for earlier detection of response that is now widely used and appreciated. These modalities along with ultrasound and optical imaging (bioluminescence, fluorescence, near-infrared imaging, multispectral imaging) have become used increasingly in preclinical studies in animal models to document the effects of genetic alterations on cancer progression or metastases, the detection of minimal residual disease, and response to various therapeutics including radiation, chemotherapy, or biologic agents. The field of molecular imaging offers potential to deliver a variety of probes that can image noninvasively drug targets, drug distribution, cancer gene expression, cell surface receptor or oncoprotein levels, and biomarker predictors of prognosis, therapeutic response, or failure. Some applications are best suited to accelerate preclinical anticancer drug development, whereas other technologies may be directly transferable to the clinic. Efforts are underway to apply noninvasive in vivo imaging to specific preclinical or clinical problems to accelerate progress in the field. Because resources are limited, and patient suffering from failed or ineffective therapy continues, a concerted effort is being made to address these issues. Many simultaneous activities involving academia; the pharmaceutical, device, and biotechnology industries; US Food and Drug Administration; National Cancer Institute; Centers for Medicare and Medicaid Services; and specialized networks sponsored by the National Institutes of Health are beginning to address these issues to develop consensus recommendations and progress in this important area.
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Affiliation(s)
- Wafik S El-Deiry
- Department of Medicine (Hematology/Oncology), the Abramson Comprehensive Cancer Center, and the Institute for Translational Medicine and Therapeutics, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA.
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38
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Abstract
Ewing's sarcoma and related tumors (ESFT) are characterized by rearrangements of EWS with ets family genes. While detection of these gene fusions greatly facilitated diagnosis, it has not provided any clues about the tissue of origin. Immunological and gene expression profiling studies favour a neuroectodermal histogenesis. These investigations did not appreciate the impact of EWS-ets proteins on the tumor phenotype. Introduction of EWS-ets into different cellular models resulted in diverse outcomes ranging from the induction of cell cycle arrest or apoptosis to transformation and tumorigenicity, and from blocked differentiation to trans-differentiation. Thus, the molecular signature of EWS-ets proteins depends on the cell type. The hen or egg problem in ESFT, therefore, is whether ESFT reflect the phenotype of the tumor stem cell that is blocked in differentiation by the activity of the EWS-ets gene fusion or if the oncogene imposes an incomplete differentiation program on a pluripotent precursor cell. This article addresses the problem by considering the tissue distribution of FLI1 and ERG expression and by reviewing evidence for combinatorial control of EWS-ets activity.
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Affiliation(s)
- Heinrich Kovar
- Children's Cancer Research Institute, St. Anna Kinderspital, Kinderspitalgasse 6, A-1090 Vienna, Austria.
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39
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Uren A, Toretsky JA. Ewing's sarcoma oncoprotein EWS-FLI1: the perfect target without a therapeutic agent. Future Oncol 2006; 1:521-8. [PMID: 16556028 DOI: 10.2217/14796694.1.4.521] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Ewing's sarcoma family of tumors (ESFT) affect patients between the ages of 3 and 40 years, with most cases occurring in the second decade of life. ESFTs are characterized by a translocation that occurs in 95% of tumors. This translocation joins the Ewing's sarcoma gene (EWS) located on chromosome 22 to an ets family gene; either friend leukemia insertion (FLI)1 located on chromosome 11, t(11;22), or ets-related gene (ERG) located on chromosome 21, t(21;22). The EWS-FLI1 fusion transcript encodes a 68 kDa protein with two primary domains. The EWS domain is a potent transcriptional activator, while the FLI1 domain contains a highly conserved ets DNA binding domain. ESFT presents a clinical challenge, especially in patients with metastatic disease in which dose-intensifying chemotherapy with bone-marrow transplantation does not improve survival. EWS-FLI1 is only present in ESFT cells and does not exist in any normal cell of the body. Experiments using ESFT cell lines or animal xenograft models have proven that EWS-FLI1 is required for tumor survival. Therefore, ESFT contains a unique protein generated by a tumor-specific translocation that has great potential as a molecular target for therapy. However, therapeutic applications directed towards eliminating or inactivating EWS-FLI1 have not reached the clinic. EWS-FLI1 has been a very difficult molecule to directly analyze in vitro due to poor solubility. Recent advances in generating recombinant EWS-FLI1 and novel data on the cellular functions of EWS-FLI1 should enhance progress towards understanding and application.
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Affiliation(s)
- Aykut Uren
- Georgetown University School of Medicine, Lombardi Comprehensive Cancer Center, 3970 Reservoir Road North West, New Research Building, Room W316, Washington DC, WA 20057, USA.
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40
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Kontny U. Regulation of apoptosis and proliferation in Ewing's sarcoma--opportunities for targeted therapy. Hematol Oncol 2006; 24:14-21. [PMID: 16400699 DOI: 10.1002/hon.766] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The Ewing's sarcoma family of tumors are malignant tumors of bone and soft tissue which occur predominantely in children and adolescents. Whereas cure rates for patients with localized tumors are around 70%, survival rates for patients with metastases or relapse are poor in spite of intensive chemo- and radiation therapy, demonstrating a clear need for new, more effective therapies. Insights into the biology of the tumors of the Ewing's sarcoma family with identification of the EWS/ETS gene rearrangement as the key event in malignant transformation and its influence on the regulation of various pathways involved in proliferation, differentiation and apoptosis has led to the identification of potential targets for the development of new molecular therapeutics. This review will focus on the regulation of major pathways of proliferation and apoptosis in tumors of the Ewing's sarcoma family and point out how modulation of these pathways might be of potential use for future therapy.
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Affiliation(s)
- Udo Kontny
- Division of Pediatric Hematology and Oncology, Department of Pediatrics and Adolescent Medicine, University of Freiburg, Germany.
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41
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Ye D, Wolff N, Li L, Zhang S, Ilaria RL. STAT5 signaling is required for the efficient induction and maintenance of CML in mice. Blood 2006; 107:4917-25. [PMID: 16522816 PMCID: PMC1895818 DOI: 10.1182/blood-2005-10-4110] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The role of signal transducers and activators of transcription 5 (STAT5) in chronic myelogenous leukemia (CML) is controversial. To clarify the role of STAT5 signaling in P210(BCR/ABL) leukemogenesis, P210 was introduced into primary murine STAT5A-deficient (STAT5A(-/-)) bone marrow (BM) cells, which, unlike STAT5A/5B double knockout BM cells, have no major intrinsic hematopoietic defects. Interestingly, only 21% of mice reconstituted with P210-transduced STAT5A(-/-) BM cells developed classic CML, compared with 80% to 100% of P210/STAT5A(+/+) and P210/STAT5A(+/-)-reconstituted animals. The remainder of P210/STAT5A(-/-) animals died from an acute B-cell lymphoblastic leukemia (ALL)-like disease (32%) or a CML/ALL mix (47%), reflecting impairment in the induction and maintenance of CML, which normally predominates in this mouse model. Of mice that ultimately developed CML, P210/STAT5A(-/-) animals had prolonged survival and increased myeloid immaturity. Importantly, reconstitution of wild-type mice with BM cells coexpressing P210 and dominant-negative STAT5 also profoundly reduced the incidence of CML, without impairing the induction of ALL. Altogether, these findings indicate that STAT5 and STAT5A play an important role in the pathogenesis of the CML-like disease in mice. A greater understanding of the STAT5 target genes involved in CML induction may lead to new therapeutic targets that influence CML progenitor cell biology.
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MESH Headings
- Animals
- Bone Marrow Cells/metabolism
- Bone Marrow Cells/pathology
- Bone Marrow Transplantation
- Burkitt Lymphoma/genetics
- Burkitt Lymphoma/metabolism
- Cell Transformation, Neoplastic/genetics
- Cell Transformation, Neoplastic/metabolism
- Drug Design
- Enzyme Inhibitors/therapeutic use
- Genes, abl/genetics
- Hematopoiesis/genetics
- Leukemia, Myelogenous, Chronic, BCR-ABL Positive/drug therapy
- Leukemia, Myelogenous, Chronic, BCR-ABL Positive/genetics
- Leukemia, Myelogenous, Chronic, BCR-ABL Positive/metabolism
- Leukemia, Myelogenous, Chronic, BCR-ABL Positive/pathology
- Mice
- Mice, Knockout
- STAT5 Transcription Factor/antagonists & inhibitors
- STAT5 Transcription Factor/deficiency
- STAT5 Transcription Factor/metabolism
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Affiliation(s)
- Dan Ye
- Department of Medicine, University of Texas Southwestern Medical Center, Dallas, USA
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42
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Castillero-Trejo Y, Eliazer S, Xiang L, Richardson JA, Ilaria RL. Expression of the EWS/FLI-1 oncogene in murine primary bone-derived cells Results in EWS/FLI-1-dependent, ewing sarcoma-like tumors. Cancer Res 2005; 65:8698-705. [PMID: 16204038 DOI: 10.1158/0008-5472.can-05-1704] [Citation(s) in RCA: 111] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Ewing sarcoma is the second most common malignant pediatric bone tumor. Over 80% of Ewing sarcoma contain the oncogene EWS/FLI-1, which encodes the EWS/FLI-1 oncoprotein, a hybrid transcription factor comprised of NH2-terminal sequences from the RNA-binding protein EWS and the DNA-binding and COOH-terminal regions of the Ets transcription factor FLI-1. Although numerous genes are dysregulated by EWS/FLI-1, advances in Ewing sarcoma cancer biology have been hindered by the lack of an animal model because of EWS/FLI-1-mediated cytotoxicity. In this study, we have developed conditions for the isolation and propagation of murine primary bone-derived cells (mPBDC) that stably express EWS/FLI-1. Early-passage EWS/FLI-1 mPBDCs were immortalized in culture but inefficient at tumor induction, whereas later-passage cells formed sarcomatous tumors in immunocompetent syngeneic mice. Murine EWS/FLI-1 tumors contained morphologically primitive cells that lacked definitive lineage markers. Molecular characterization of murine EWS/FLI-1 tumors revealed that some but not all had acquired a novel, clonal in-frame p53 mutation associated with a constitutive loss of p21 expression. Despite indications that secondary events facilitated EWS/FLI-1 mPBDC tumorigenesis, cells remained highly dependent on EWS/FLI-1 for efficient transformation in clonogenic assays. This Ewing sarcoma animal model will be a useful tool for dissecting the molecular pathogenesis of Ewing sarcoma and provides rationale for the broader use of organ-specific progenitor cell populations for the study of human sarcoma.
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MESH Headings
- Amino Acid Sequence
- Animals
- Bone Neoplasms/genetics
- Bone Neoplasms/metabolism
- Bone Neoplasms/pathology
- Cell Cycle/physiology
- Cell Transformation, Neoplastic/genetics
- Cell Transformation, Neoplastic/metabolism
- Cell Transformation, Neoplastic/pathology
- Disease Models, Animal
- Gene Expression
- Mice
- Mice, Inbred BALB C
- Molecular Sequence Data
- Oncogene Proteins, Fusion/biosynthesis
- Oncogene Proteins, Fusion/genetics
- Proto-Oncogene Protein c-fli-1/biosynthesis
- Proto-Oncogene Protein c-fli-1/genetics
- RNA-Binding Protein EWS/biosynthesis
- RNA-Binding Protein EWS/genetics
- Sarcoma, Ewing/genetics
- Sarcoma, Ewing/metabolism
- Sarcoma, Ewing/pathology
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Affiliation(s)
- Yeny Castillero-Trejo
- Hamon Center for Therapeutic Oncology Research, Department of Pathology, Division of Hematology/Oncology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
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43
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Xia SJ, Barr FG. Chromosome translocations in sarcomas and the emergence of oncogenic transcription factors. Eur J Cancer 2005; 41:2513-27. [PMID: 16213703 DOI: 10.1016/j.ejca.2005.08.003] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
A subset of sarcomas is characterised by recurrent chromosome translocations that generate novel fusion oncoproteins. One or both of the genes involved in these translocations often encode transcription factors, and the resulting fusion proteins have aberrant transcriptional function compared to their wild-type counterparts. These fusion transcription factors disrupt multiple biological pathways by altering expression of target genes, and thereby result in a variety of altered cellular properties that contribute to the tumourigenic process. However, experimental data indicate that the fusion gene alone is not sufficient for transformation in primary cells (EWS-FLI1) or tumourigenesis in the mouse (PAX3-FKHR, FUS-CHOP), suggesting that additional collaborating genetic alterations are required. In addition to improving our understanding of the etiology of these tumours, this accumulating knowledge of the oncogenic properties of these fusion proteins, their downstream targets, and cooperating genetic alterations will permit the development of a variety of novel approaches to improve the therapy of these cancers.
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Affiliation(s)
- Shujuan J Xia
- Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine, 505C Stellar Chance Laboratories, 422 Curie Boulevard, Philadelphia, PA 19104-6082, USA
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44
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Li X, Tanaka K, Nakatani F, Matsunobu T, Sakimura R, Hanada M, Okada T, Nakamura T, Iwamoto Y. Transactivation of cyclin E gene by EWS-Fli1 and antitumor effects of cyclin dependent kinase inhibitor on Ewing's family tumor cells. Int J Cancer 2005; 116:385-94. [PMID: 15818598 DOI: 10.1002/ijc.21010] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Chromosomal translocation t(11; 22)(q24; q12) is detected in approximately 90% of Ewing's family tumors (EFTs) including Ewing's sarcoma and primitive neuroectodermal tumor. This results in the formation of the EWS-Fli1 fusion gene, which produces EWS-Fli1 fusion protein. This chimerical gene product acts as an aberrant transcriptional activator, which may be responsible for the tumorigenesis of EFTs. We have previously reported that cyclin E expression was upregulated in EFT cells and in EWS-Fli1 transformed fibroblastic cells. However, the mechanism of the overexpression of cyclin E by EWS-Fli1 is still unknown. In our study, we investigated the mechanism of transactivation of the cyclin E gene in EFT cells. We found that EWS-Fli1 enhanced the activity of the cyclin E gene promoter partially through E2F binding sites in the promoter. In addition, the basic transcriptional factor, Sp1, might also be involved in the transactivation of the cyclin E gene by EWS-Fli1. To study the biological significance of cyclin E overexpression in EFT cells, we used flavopiridol, a pan-cyclin-dependent kinase (CDK) inhibitor and found that flavopiridol efficiently suppressed the growth of EFT cells in vitro and in vivo by the inhibition of cyclinE/CDK2 kinase activity and the induction of apoptosis. These results suggest that targeting of the cyclin/CDK complex may provide new insight into treatment of EFTs.
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Affiliation(s)
- Xu Li
- Department of Orthopaedic Surgery, Graduate School of Medical Sciences, Kyushu University, Higashi-ku, Fukuoka, Japan
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45
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Hu-Lieskovan S, Zhang J, Wu L, Shimada H, Schofield DE, Triche TJ. EWS-FLI1 fusion protein up-regulates critical genes in neural crest development and is responsible for the observed phenotype of Ewing's family of tumors. Cancer Res 2005; 65:4633-44. [PMID: 15930281 DOI: 10.1158/0008-5472.can-04-2857] [Citation(s) in RCA: 123] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Tumor-specific translocations are common in tumors of mesenchymal origin. Whether the translocation determines the phenotype, or vice versa, is debatable. Ewing's family tumors (EFT) are consistently associated with an EWS-FLI1 translocation and a primitive neural phenotype. Histogenesis and classification are therefore uncertain. To test whether EWS-FLI1 fusion gene expression is responsible for the primitive neuroectodermal phenotype of EFT, we established a tetracycline-inducible EWS-FLI1 expression system in a rhabdomyosarcoma cell line RD. Cell morphology changed after EWS-FLI1 expression, resembling cultured EFT cells. Xenografts showed typical EFT features, distinct from tumors formed by parental RD. Neuron-specific microtubule gene MAPT, parasympathetic marker cholecystokinin, and epithelial marker keratin 18 were up-regulated. Conversely, myogenesis was diminished. Comparison of the up-regulated genes in RD-EF with the Ewing's signature genes identified important EWS-FLI1 downstream genes, many involved in neural crest differentiation. These results were validated by real-time reverse transcription-PCR analysis and RNA interference technology using small interfering RNA against EWS-FLI1 breakpoint. The present study shows that the neural phenotype of Ewing's tumors is attributable to the EWS-FLI1 expression and the resultant phenotype resembles developing neural crest. Such tumors have a limited neural phenotype regardless of tissue of origin. These findings challenge traditional views of histogenesis and tumor origin.
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MESH Headings
- Animals
- Cell Differentiation/genetics
- Cell Line, Tumor
- Gene Expression Regulation, Developmental/genetics
- Gene Expression Regulation, Neoplastic/genetics
- Humans
- Mice
- Mice, SCID
- Neoplasm Transplantation
- Neural Crest/embryology
- Neural Crest/metabolism
- Neural Crest/physiology
- Oncogene Proteins, Fusion/genetics
- Proto-Oncogene Protein c-fli-1
- RNA-Binding Protein EWS
- Rhabdomyosarcoma, Embryonal/genetics
- Rhabdomyosarcoma, Embryonal/metabolism
- Rhabdomyosarcoma, Embryonal/pathology
- Sarcoma, Ewing/genetics
- Sarcoma, Ewing/metabolism
- Sarcoma, Ewing/pathology
- Transcription Factors/genetics
- Transfection
- Transplantation, Heterologous
- Up-Regulation
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Affiliation(s)
- Siwen Hu-Lieskovan
- Department of Pathology and Laboratory Medicine, Children's Hospital Los Angeles, Keck School of Medicine, University of Southern California, Los Angeles, California 90027, USA
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46
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Abstract
Sarcomas comprise a heterogeneous group of malignancies that are derived from mesenchymal cells, which under normal circumstances lead to the development of connective tissues such as bone, muscle, fat, and cartilage. During the past decade, insight has been gained regarding the aberrancies that occur during normal development that result in mesenchymal cells transforming into sarcomas. More recently, these insights have led to the development of successful therapies that target the specific mechanisms inherent to individual sarcomas. This overview discusses some of the aberrant molecular mechanisms shared in sarcomas and reviews several sarcoma subtypes in which the most advances have been made. Finally, the ways in which these advances in basic science are translating into and redefining clinical practice are highlighted.
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Affiliation(s)
- Igor Matushansky
- Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10021, USA.
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47
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Nozawa S, Ohno T, Banno Y, Dohjima T, Wakahara K, Fan DG, Shimizu K. Inhibition of platelet-derived growth factor-induced cell growth signaling by a short interfering RNA for EWS-Fli1 via down-regulation of phospholipase D2 in Ewing sarcoma cells. J Biol Chem 2005; 280:27544-51. [PMID: 15919668 DOI: 10.1074/jbc.m411626200] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
EWS-Fli1, a fusion gene resulting from a chromosomal translocation t(11;22, q24;q12) and found in Ewing sarcoma and primitive neuroectodermal tumors, encodes a transcriptional activator and promotes cellular transformation. However, the precise biological functions of its products remain unknown. To investigate the role of EWS-Fli1 in cell growth signaling, we transfected Ewing sarcoma TC-135 cells with short interfering RNAs for EWS-Fli1. EWS-Fli1 knockdown reduced cell growth and platelet-derived growth factor (PDGF)-BB-induced activation of the growth signaling enzymes. Interestingly, phospholipase D2 (but not the PDGF-BB receptor) showed marked down-regulation in the EWS-Fli1-knocked down TC-135 cells compared with the control cells. In Ewing sarcoma TC-135 cells, the PDGF-BB-induced phosphorylation of growth signaling involving extracellular signal-regulated kinase, Akt, p70S6K, and the expression of cyclin D3 were markedly inhibited by transfection with short interfering RNA phospholipase (PL)-D2. The PDGF-BB-induced activation of growth signaling was also suppressed by 1-butanol, which prevents the production of phosphatidic acid by phospholipase D (but not by t-butyl alcohol), thereby implicating PLD2 in PDGF-BB-mediated signaling in TC-135 cells. These results suggest that EWS-Fli1 may play a role in the regulation of tumor proliferation-signaling enzymes via PLD2 expression in Ewing sarcoma cells.
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MESH Headings
- Becaplermin
- Blotting, Western
- Cell Line, Tumor
- Cell Proliferation
- Cyclin D3
- Cyclins/biosynthesis
- Dose-Response Relationship, Drug
- Down-Regulation
- Enzyme Inhibitors/pharmacology
- Gene Expression Regulation, Neoplastic
- Humans
- Models, Biological
- Oncogene Proteins, Fusion/genetics
- Oncogene Proteins, Fusion/metabolism
- Phospholipase D/biosynthesis
- Phosphorylation
- Platelet-Derived Growth Factor/antagonists & inhibitors
- Platelet-Derived Growth Factor/metabolism
- Proto-Oncogene Protein c-fli-1
- Proto-Oncogene Proteins c-sis
- RNA, Small Interfering/metabolism
- RNA-Binding Protein EWS
- Ribosomal Protein S6 Kinases, 70-kDa/metabolism
- Sarcoma, Ewing/metabolism
- Signal Transduction
- Time Factors
- Transcription Factors/genetics
- Transcription Factors/metabolism
- Transcriptional Activation
- Transfection
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Affiliation(s)
- Satoshi Nozawa
- Department of Orthopaedic Surgery, Gifu University School of Medicine, 1-1 Yanagido, Gifu 501-1194, Japan
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48
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Siligan C, Ban J, Bachmaier R, Spahn L, Kreppel M, Schaefer KL, Poremba C, Aryee DNT, Kovar H. EWS-FLI1 target genes recovered from Ewing's sarcoma chromatin. Oncogene 2005; 24:2512-24. [PMID: 15735734 DOI: 10.1038/sj.onc.1208455] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
In all, 85% of Ewing's sarcoma family tumors (ESFT), a neoplasm of unknown histogenesis, express EWS-FLI1 transcription factor gene fusions. To characterize direct target genes avoiding artificial model systems, we cloned genomic DNA from ESFT chromatin precipitating with EWS-FLI1. We now present a comprehensive list of 99 putative transcription factor targets identified, for the first time, by a hypothesis-free approach based on physical interaction. Gene-derived chromatin fragments co-precipitating with EWS-FLI1 were nonrandomly distributed over the human genome and localized predominantly to the upstream region and the first two introns of the genes. At least 20% of putative direct EWS-FLI1 targets were neural genes. One-third of genes recovered showed a significant ESFT-specific expression pattern and were found to be altered upon RNAi-mediated knockdown of EWS-FLI1. Among them, MK-STYX, encoding a MAP kinase phosphatase-like protein, was consistently expressed in ESFT. EWS-FLI1 was found to drive MK-STYX expression by binding to a single ETS binding motif within the first gene intron. MK-STYX serves as precedence for successful recovery of direct EWS-FLI1 targets from the authentic ESFT cellular context, the most relevant system to study oncogenic mechanisms for the discovery of new therapeutic targets in this disease.
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Affiliation(s)
- Christine Siligan
- Children's Cancer Research Institute (CCRI), St Anna Kinderspital, Kinderspitalgasse 6, Vienna A1090, Austria
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Liu CJ, Chang E, Yu J, Carlson CS, Prazak L, Yu XP, Ding B, Lengyel P, Di Cesare PE. The Interferon-inducible p204 Protein Acts as a Transcriptional Coactivator of Cbfa1 and Enhances Osteoblast Differentiation. J Biol Chem 2005; 280:2788-96. [PMID: 15557274 DOI: 10.1074/jbc.m412604200] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The differentiation of uncommitted mesenchymal cells into osteoblasts is a fundamental molecular event governing both embryonic development and bone repair. The bone morphogenetic proteins (BMPs) are important regulators of this process; they function by binding to cell surface receptors and signaling by means of Smad proteins. Core binding factor alpha-1 (Cbfa1), a member of the runt family of transcription factors, is an essential transcriptional regulator of osteoblast differentiation and bone formation, and this process is positively or negatively regulated by a variety of coactivators and corepressors. We report that p204, an interferon-inducible protein that was previously shown to inhibit cell proliferation and promote the differentiation of myoblasts to myotubes, is a novel regulator in the course of osteogenesis. p204 is expressed in embryonic osteoblasts and hypertrophic chondrocytes in the growth plate as well as in the calvaria osteoblasts of neonatal mice. Its level is increased in the course of the BMP-2-triggered osteoblast differentiation of pluripotent C2C12 cells. This increase is probably due to the activation of the gene encoding 204 (Ifi204) by Smad transcription factor, including Smad1, -4, and -5. Overexpression of p204 enhances the BMP-2-induced osteoblast differentiation in vitro, as revealed by elevated alkaline phosphatase activity and osteocalcin production. p204 acts as a cofactor of Cbfa1: 1) high levels of p204 augment, whereas the lowering of p204 level decreases, the Cbfa1-dependent transcription, and 2) p204 associates with Cbfa1 both in vitro and in vivo. Two nonoverlapping segments in p204 bind to Cbfa1, and the N-terminal 88-amino acid segment of Cbfa1 is required for binding to p204. p204, which is the first interferon-inducible protein found to associate with Cbfa1, functions as a novel regulator of osteoblast differentiation.
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Affiliation(s)
- Chuan-Ju Liu
- Musculoskeletal Research Center and Department of Orthopaedic Surgery, New York University, Hospital for Joint Diseases, New York, New York 10003, USA.
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Zhang J, Hu S, Schofield DE, Sorensen PHB, Triche TJ. Selective Usage of D-Type Cyclins by Ewing’s Tumors and Rhabdomyosarcomas. Cancer Res 2004; 64:6026-34. [PMID: 15342383 DOI: 10.1158/0008-5472.can-03-2594] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The genetic mechanisms that control proliferation of childhood musculoskeletal malignancies, notably Ewing's tumor (ET) and rhabdomyosarcoma (RMS), remain largely unknown. Most human cancers appear to overexpress at least one of the G1 cyclins (cyclins D1, D2, D3, E1, and E2) to bypass normal regulation of cell cycle G1 progression. We compared the gene expression profiles of 7 ET and 13 RMS primary tumor samples and found overexpression of cyclin D1 in all 7 ET samples. In contrast, RMS samples expressed higher levels of cyclin D2, cyclin D3, and cyclin E1. This was confirmed by quantitative reverse transcription-polymerase chain reaction and Western blot. The relative roles of RAS-extracellular signal-regulated kinase 1/2 and phosphatidylinositol 3'-kinase (PI3K)-AKT pathways in the regulation of D-type cyclin expression in these tumors were then assessed. Inhibition of either pathway reduced expression of cyclins D1, D2, and D3 in RMS lines, whereas only PI3K inhibitors blocked cyclin D1, D2, and D3 expression in ET lines. Furthermore, PI3K-AKT appeared to regulate D-type cyclin transcription in RMS lines through FKHR and FKHRL1. Finally, the role of the ET-associated EWS-FLI1 fusion gene in regulating D cyclin expression was studied. Inhibition of EWS-FLI1 expression in the TC71 ET line decreased cyclin D1 levels but increased cyclin D3 levels. In contrast, induction of EWS-FLI1 expression in the RD RMS cell line increased cyclin D1 expression but decreased cyclin D3 expression. Our results demonstrate distinct regulation of D-type cyclins in ET and RMS and indicate that EWS-FLI1 can modulate the expression of D-type cyclins independent of cellular backgrounds.
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Affiliation(s)
- Jingsong Zhang
- Department of Pathology and Laboratory Medicine, Children's Hospital Los Angeles, Keck School of Medicine, University of Southern California, Los Angeles, California 90027, USA
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