1
|
Tan XL, Wang Z, Liao S, Yi M, Tao D, Zhang X, Leng X, Shi J, Xie S, Yang Y, Liu YQ. NR0B1 augments sorafenib resistance in hepatocellular carcinoma through promoting autophagy and inhibiting apoptosis. Cancer Sci 2024; 115:465-476. [PMID: 37991109 PMCID: PMC10859617 DOI: 10.1111/cas.16029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Revised: 11/06/2023] [Accepted: 11/10/2023] [Indexed: 11/23/2023] Open
Abstract
NR0B1 is frequently activated in hepatocellular carcinoma (HCC). However, the role of NR0B1 is controversial in HCC. In this study, we observed that NR0B1 was an independent poor prognostic factor, negatively correlated with the overall survival of HCC and the relapse-free survival of patients treated with sorafenib. Meanwhile, NR0B1 promoted the proliferation, migration, and invasion of HCC cells, inhibited sorafenib-induced apoptosis, and elevated the IC50 of sorafenib in HCC cells. NR0B1 was further displayed to increase sorafenib-induced autophagic vesicles and activate Beclin1/LC3-II-dependent autophagy pathway. Finally, NR0B1 was revealed to transcriptionally suppress GSK3β that restrains AMPK/mTOR-driven autophagy and increases BAX-mediated apoptosis. Collectively, our study uncovered that the ectopic expression of NR0B1 augmented sorafenib-resistance in HCC cells by activating autophagy and inhibiting apoptosis. Our findings supported that NR0B1 was a detrimental factor for HCC prognosis.
Collapse
Affiliation(s)
- Xiao lan Tan
- Department of Medical Genetics and State Key Laboratory of Biotherapy, West China HospitalSichuan UniversityChengduChina
| | - Zhaokun Wang
- Department of Medical Genetics and State Key Laboratory of Biotherapy, West China HospitalSichuan UniversityChengduChina
| | - Shunyao Liao
- Institute of Gerontology and Center for Geriatrics, Sichuan Academy of Medical Sciences & Sichuan Provincial People's HospitalUniversity of Electronic Science and Technology of ChinaChengduChina
| | - Ming Yi
- Department of Medical Genetics and State Key Laboratory of Biotherapy, West China HospitalSichuan UniversityChengduChina
| | - Dachang Tao
- Department of Medical Genetics and State Key Laboratory of Biotherapy, West China HospitalSichuan UniversityChengduChina
| | - Xinyue Zhang
- Department of Medical Genetics and State Key Laboratory of Biotherapy, West China HospitalSichuan UniversityChengduChina
| | - Xiangyou Leng
- Department of Medical Genetics and State Key Laboratory of Biotherapy, West China HospitalSichuan UniversityChengduChina
| | - Jiaying Shi
- Department of Medical Genetics and State Key Laboratory of Biotherapy, West China HospitalSichuan UniversityChengduChina
| | - Shengyu Xie
- Department of Medical Genetics and State Key Laboratory of Biotherapy, West China HospitalSichuan UniversityChengduChina
| | - Yuan Yang
- Department of Medical Genetics and State Key Laboratory of Biotherapy, West China HospitalSichuan UniversityChengduChina
| | - Yun qiang Liu
- Department of Medical Genetics and State Key Laboratory of Biotherapy, West China HospitalSichuan UniversityChengduChina
| |
Collapse
|
2
|
Yasir M, Park J, Chun W. EWS/FLI1 Characterization, Activation, Repression, Target Genes and Therapeutic Opportunities in Ewing Sarcoma. Int J Mol Sci 2023; 24:15173. [PMID: 37894854 PMCID: PMC10607184 DOI: 10.3390/ijms242015173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Revised: 10/11/2023] [Accepted: 10/12/2023] [Indexed: 10/29/2023] Open
Abstract
Despite their clonal origins, tumors eventually develop into complex communities made up of phenotypically different cell subpopulations, according to mounting evidence. Tumor cell-intrinsic programming and signals from geographically and temporally changing microenvironments both contribute to this variability. Furthermore, the mutational load is typically lacking in childhood malignancies of adult cancers, and they still exhibit high cellular heterogeneity levels largely mediated by epigenetic mechanisms. Ewing sarcomas represent highly aggressive malignancies affecting both bone and soft tissue, primarily afflicting adolescents. Unfortunately, the outlook for patients facing relapsed or metastatic disease is grim. These tumors are primarily fueled by a distinctive fusion event involving an FET protein and an ETS family transcription factor, with the most prevalent fusion being EWS/FLI1. Despite originating from a common driver mutation, Ewing sarcoma cells display significant variations in transcriptional activity, both within and among tumors. Recent research has pinpointed distinct fusion protein activities as a principal source of this heterogeneity, resulting in markedly diverse cellular phenotypes. In this review, we aim to characterize the role of the EWS/FLI fusion protein in Ewing sarcoma by exploring its general mechanism of activation and elucidating its implications for tumor heterogeneity. Additionally, we delve into potential therapeutic opportunities to target this aberrant fusion protein in the context of Ewing sarcoma treatment.
Collapse
Affiliation(s)
| | | | - Wanjoo Chun
- Department of Pharmacology, Kangwon National University School of Medicine, Chuncheon 24341, Republic of Korea; (M.Y.); (J.P.)
| |
Collapse
|
3
|
Fernández-Tabanera E, García-García L, Rodríguez-Martín C, Cervera ST, González-González L, Robledo C, Josa S, Martínez S, Chapado L, Monzón S, Melero-Fernández de Mera RM, Alonso J. CD44 Modulates Cell Migration and Invasion in Ewing Sarcoma Cells. Int J Mol Sci 2023; 24:11774. [PMID: 37511533 PMCID: PMC10381016 DOI: 10.3390/ijms241411774] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Revised: 07/18/2023] [Accepted: 07/19/2023] [Indexed: 07/30/2023] Open
Abstract
The chimeric EWSR1::FLI1 transcription factor is the main oncogenic event in Ewing sarcoma. Recently, it has been proposed that EWSR1::FLI1 levels can fluctuate in Ewing sarcoma cells, giving rise to two cell populations. EWSR1::FLI1low cells present a migratory and invasive phenotype, while EWSR1::FLI1high cells are more proliferative. In this work, we described how the CD44 standard isoform (CD44s), a transmembrane protein involved in cell adhesion and migration, is overexpressed in the EWSR1::FLI1low phenotype. The functional characterization of CD44s (proliferation, clonogenicity, migration, and invasion ability) was performed in three doxycycline-inducible Ewing sarcoma cell models (A673, MHH-ES1, and CADO-ES1). As a result, CD44s expression reduced cell proliferation in all the cell lines tested without affecting clonogenicity. Additionally, CD44s increased cell migration in A673 and MHH-ES1, without effects in CADO-ES1. As hyaluronan is the main ligand of CD44s, its effect on migration ability was also assessed, showing that high molecular weight hyaluronic acid (HMW-HA) blocked cell migration while low molecular weight hyaluronic acid (LMW-HA) increased it. Invasion ability was correlated with CD44 expression in A673 and MHH-ES1 cell lines. CD44s, upregulated upon EWSR1::FLI1 knockdown, regulates cell migration and invasion in Ewing sarcoma cells.
Collapse
Affiliation(s)
- Enrique Fernández-Tabanera
- Unidad de Tumores Sólidos Infantiles, Instituto de Investigación de Enfermedades Raras (IIER), Instituto de Salud Carlos III (ISCIII), 28220 Madrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras, Instituto de Salud Carlos III (U758, CB06/07/1009, CIBERER-ISCIII), 28029 Madrid, Spain
- Universidad Nacional de Educación a Distancia (UNED), 28015 Madrid, Spain
| | - Laura García-García
- Unidad de Tumores Sólidos Infantiles, Instituto de Investigación de Enfermedades Raras (IIER), Instituto de Salud Carlos III (ISCIII), 28220 Madrid, Spain
| | - Carlos Rodríguez-Martín
- Unidad de Tumores Sólidos Infantiles, Instituto de Investigación de Enfermedades Raras (IIER), Instituto de Salud Carlos III (ISCIII), 28220 Madrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras, Instituto de Salud Carlos III (U758, CB06/07/1009, CIBERER-ISCIII), 28029 Madrid, Spain
| | - Saint T Cervera
- Unidad de Tumores Sólidos Infantiles, Instituto de Investigación de Enfermedades Raras (IIER), Instituto de Salud Carlos III (ISCIII), 28220 Madrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras, Instituto de Salud Carlos III (U758, CB06/07/1009, CIBERER-ISCIII), 28029 Madrid, Spain
| | - Laura González-González
- Unidad de Tumores Sólidos Infantiles, Instituto de Investigación de Enfermedades Raras (IIER), Instituto de Salud Carlos III (ISCIII), 28220 Madrid, Spain
| | - Cristina Robledo
- Unidad de Tumores Sólidos Infantiles, Instituto de Investigación de Enfermedades Raras (IIER), Instituto de Salud Carlos III (ISCIII), 28220 Madrid, Spain
| | - Santiago Josa
- Unidad de Tumores Sólidos Infantiles, Instituto de Investigación de Enfermedades Raras (IIER), Instituto de Salud Carlos III (ISCIII), 28220 Madrid, Spain
| | - Selene Martínez
- Unidad de Tumores Sólidos Infantiles, Instituto de Investigación de Enfermedades Raras (IIER), Instituto de Salud Carlos III (ISCIII), 28220 Madrid, Spain
| | - Luis Chapado
- Bioinformatics Unit, Instituto de Salud Carlos III (ISCIII), 28220 Madrid, Spain
| | - Sara Monzón
- Bioinformatics Unit, Instituto de Salud Carlos III (ISCIII), 28220 Madrid, Spain
| | - Raquel M Melero-Fernández de Mera
- Unidad de Tumores Sólidos Infantiles, Instituto de Investigación de Enfermedades Raras (IIER), Instituto de Salud Carlos III (ISCIII), 28220 Madrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras, Instituto de Salud Carlos III (U758, CB06/07/1009, CIBERER-ISCIII), 28029 Madrid, Spain
| | - Javier Alonso
- Unidad de Tumores Sólidos Infantiles, Instituto de Investigación de Enfermedades Raras (IIER), Instituto de Salud Carlos III (ISCIII), 28220 Madrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras, Instituto de Salud Carlos III (U758, CB06/07/1009, CIBERER-ISCIII), 28029 Madrid, Spain
| |
Collapse
|
4
|
Watanabe M, Kosaka H, Sugawara M, Maemoto M, Ono Y, Uemori T, Shizu R, Yoshinari K. Screening for DAX1/EWS-FLI1 functional inhibitors identified dihydroorotate dehydrogenase as a therapeutic target for Ewing's sarcoma. Cancer Med 2023; 12:9802-9814. [PMID: 36825574 PMCID: PMC10166890 DOI: 10.1002/cam4.5741] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 11/27/2022] [Accepted: 02/14/2023] [Indexed: 02/25/2023] Open
Abstract
OBJECTIVE EWS-FLI1 is the most common oncogenic fusion protein in Ewing's sarcoma family tumors (ESFTs). DAX1, an orphan member of the nuclear receptor superfamily, is up-regulated by EWS-FLI1 and plays a key role in the transformed phenotype of ESFTs. METHODS To discover a functional inhibitor of DAX1 and EWS-FLI1, we screened small-molecular inhibitors using a DAX1 reporter assay system. RESULTS K-234 and its derivatives, which were dihydroorotate dehydrogenase (DHODH) inhibitors, showed inhibitory effects in the reporter assay. K-234 inhibited the growth of Ewing's sarcoma with various fusion types, and K-234 derivatives altered the expression of EWS-FLI1-regulated genes. The DAX1 expression had no effect on the growth inhibitory effect of the K-234 derivatives, while DHODH overexpression or uridine treatment attenuated their inhibitory effects, suggesting that inhibition by K-234 derivatives occurs through DHODH inhibition. An in vivo study showed that a K-234 derivative clearly inhibited tumor growth in an Ewing's sarcoma xenograft mouse model. CONCLUSION Taken together, the present results suggest that DHODH inhibitors can inhibit the function of DAX1/EWS-FLI1 in ESFTs and might be a therapeutic agent with potent anti-tumor activity for Ewing's sarcoma patients.
Collapse
Affiliation(s)
- Miwa Watanabe
- Research and Development Division, Kyowa Kirin Co., Ltd., Shizuoka, Japan.,Department of Molecular Toxicology, School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka, Japan
| | - Hiromichi Kosaka
- Research and Development Division, Kyowa Kirin Co., Ltd., Shizuoka, Japan
| | - Masamori Sugawara
- Research and Development Division, Kyowa Kirin Co., Ltd., Shizuoka, Japan
| | - Michihiro Maemoto
- Research and Development Division, Kyowa Kirin Co., Ltd., Shizuoka, Japan
| | - Yoko Ono
- Research and Development Division, Kyowa Kirin Co., Ltd., Shizuoka, Japan
| | - Takeshi Uemori
- Research and Development Division, Kyowa Kirin Co., Ltd., Shizuoka, Japan
| | - Ryota Shizu
- Department of Molecular Toxicology, School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka, Japan
| | - Kouichi Yoshinari
- Department of Molecular Toxicology, School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka, Japan
| |
Collapse
|
5
|
Flores G, Grohar PJ. One oncogene, several vulnerabilities: EWS/FLI targeted therapies for Ewing sarcoma. J Bone Oncol 2021; 31:100404. [PMID: 34976713 PMCID: PMC8686064 DOI: 10.1016/j.jbo.2021.100404] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 11/18/2021] [Accepted: 11/23/2021] [Indexed: 12/23/2022] Open
Abstract
EWS/FLI is the defining mutation of Ewing sarcoma. This oncogene drives malignant transformation and progression and occurs in a genetic background characterized by few other recurrent cooperating mutations. In addition, the tumor is absolutely dependent on the continued expression of EWS/FLI to maintain the malignant phenotype. However, EWS/FLI is a transcription factor and therefore a challenging drug target. The difficulty of directly targeting EWS/FLI stems from unique features of this fusion protein as well as the network of interacting proteins required to execute the transcriptional program. This network includes interacting proteins as well as upstream and downstream effectors that together reprogram the epigenome and transcriptome. While the vast number of proteins involved in this process challenge the development of a highly specific inhibitors, they also yield numerous therapeutic opportunities. In this report, we will review how this vast EWS-FLI transcriptional network has been exploited over the last two decades to identify compounds that directly target EWS/FLI and/or associated vulnerabilities.
Collapse
Affiliation(s)
- Guillermo Flores
- Van Andel Research Institute, Grand Rapids, MI, USA
- Michigan State University, College of Human Medicine, USA
| | - Patrick J Grohar
- Children's Hospital of Philadelphia, University of Pennsylvania, Perelman School of Medicine, 3501 Civic Center Blvd., Philadelphia, PA, USA
| |
Collapse
|
6
|
Cervera ST, Rodríguez-Martín C, Fernández-Tabanera E, Melero-Fernández de Mera RM, Morin M, Fernández-Peñalver S, Iranzo-Martínez M, Amhih-Cardenas J, García-García L, González-González L, Moreno-Pelayo MA, Alonso J. Therapeutic Potential of EWSR1-FLI1 Inactivation by CRISPR/Cas9 in Ewing Sarcoma. Cancers (Basel) 2021; 13:cancers13153783. [PMID: 34359682 PMCID: PMC8345183 DOI: 10.3390/cancers13153783] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 07/13/2021] [Accepted: 07/23/2021] [Indexed: 01/14/2023] Open
Abstract
Simple Summary Ewing sarcoma is an aggressive tumor with still unacceptable survival rates, particularly in patients with metastatic disease and for which it is necessary to develop new and innovative therapies. These tumors are characterized by the presence of chromosomal translocations that give rise to chimeric transcription factors (i.e., EWSR1–FLI1) that govern the oncogenic process. In this article, we describe an efficient strategy to permanently inactivate the EWSR1–FLI1 oncogene characteristic of Ewing sarcoma using CRISPR/Cas9 gene editing technology. Although the application of gene therapy in cancer still has many limitations, for example, the strategy for delivery, studies like ours show that gene therapy can be a promising alternative, particularly for those tumors that are highly dependent on a particular oncogene as is the case in Ewing sarcoma. Abstract Ewing sarcoma is an aggressive bone cancer affecting children and young adults. The main molecular hallmark of Ewing sarcoma are chromosomal translocations that produce chimeric oncogenic transcription factors, the most frequent of which is the aberrant transcription factor EWSR1–FLI1. Because this is the principal oncogenic driver of Ewing sarcoma, its inactivation should be the best therapeutic strategy to block tumor growth. In this study, we genetically inactivated EWSR1–FLI1 using CRISPR-Cas9 technology in order to cause permanent gene inactivation. We found that gene editing at the exon 9 of FLI1 was able to block cell proliferation drastically and induce senescence massively in the well-studied Ewing sarcoma cell line A673. In comparison with an extensively used cellular model of EWSR1–FLI1 knockdown (A673/TR/shEF), genetic inactivation was more effective, particularly in its capability to block cell proliferation. In summary, genetic inactivation of EWSR1–FLI1 in A673 Ewing sarcoma cells blocks cell proliferation and induces a senescence phenotype that could be exploited therapeutically. Although efficient and specific in vivo CRISPR-Cas9 editing still presents many challenges today, our data suggest that complete inactivation of EWSR1–FLI1 at the cell level should be considered a therapeutic approach to develop in the future.
Collapse
Affiliation(s)
- Saint T. Cervera
- Unidad de Tumores Sólidos Infantiles, Instituto de Investigación de Enfermedades Raras (IIER), Instituto de Salud Carlos III (ISCIII), 28220 Madrid, Spain; (S.T.C.); (C.R.-M.); (E.F.-T.); (R.M.M.-F.d.M.); (M.I.-M.); (J.A.-C.); (L.G.-G.); (L.G.-G.)
- Centro de Investigación Biomédica en Red de Enfermedades Raras, Instituto de Salud Carlos III (CB06/07/1009; CIBERER-ISCIII), 28029 Madrid, Spain
| | - Carlos Rodríguez-Martín
- Unidad de Tumores Sólidos Infantiles, Instituto de Investigación de Enfermedades Raras (IIER), Instituto de Salud Carlos III (ISCIII), 28220 Madrid, Spain; (S.T.C.); (C.R.-M.); (E.F.-T.); (R.M.M.-F.d.M.); (M.I.-M.); (J.A.-C.); (L.G.-G.); (L.G.-G.)
- Centro de Investigación Biomédica en Red de Enfermedades Raras, Instituto de Salud Carlos III (CB06/07/1009; CIBERER-ISCIII), 28029 Madrid, Spain
| | - Enrique Fernández-Tabanera
- Unidad de Tumores Sólidos Infantiles, Instituto de Investigación de Enfermedades Raras (IIER), Instituto de Salud Carlos III (ISCIII), 28220 Madrid, Spain; (S.T.C.); (C.R.-M.); (E.F.-T.); (R.M.M.-F.d.M.); (M.I.-M.); (J.A.-C.); (L.G.-G.); (L.G.-G.)
- Centro de Investigación Biomédica en Red de Enfermedades Raras, Instituto de Salud Carlos III (CB06/07/1009; CIBERER-ISCIII), 28029 Madrid, Spain
| | - Raquel M. Melero-Fernández de Mera
- Unidad de Tumores Sólidos Infantiles, Instituto de Investigación de Enfermedades Raras (IIER), Instituto de Salud Carlos III (ISCIII), 28220 Madrid, Spain; (S.T.C.); (C.R.-M.); (E.F.-T.); (R.M.M.-F.d.M.); (M.I.-M.); (J.A.-C.); (L.G.-G.); (L.G.-G.)
- Centro de Investigación Biomédica en Red de Enfermedades Raras, Instituto de Salud Carlos III (CB06/07/1009; CIBERER-ISCIII), 28029 Madrid, Spain
| | - Matias Morin
- Servicio de Genética, Hospital Universitario Ramón y Cajal, IRYCIS, Carretera de Colmenar km 9.100, 28034 Madrid, Spain; (M.M.); (S.F.-P.); (M.A.M.-P.)
- Centro de Investigación Biomédica en Red de Enfermedades Raras, Instituto de Salud Carlos III (CB06/07/0048; CIBERER-ISCIII), 28029 Madrid, Spain
| | - Sergio Fernández-Peñalver
- Servicio de Genética, Hospital Universitario Ramón y Cajal, IRYCIS, Carretera de Colmenar km 9.100, 28034 Madrid, Spain; (M.M.); (S.F.-P.); (M.A.M.-P.)
| | - Maria Iranzo-Martínez
- Unidad de Tumores Sólidos Infantiles, Instituto de Investigación de Enfermedades Raras (IIER), Instituto de Salud Carlos III (ISCIII), 28220 Madrid, Spain; (S.T.C.); (C.R.-M.); (E.F.-T.); (R.M.M.-F.d.M.); (M.I.-M.); (J.A.-C.); (L.G.-G.); (L.G.-G.)
| | - Jorge Amhih-Cardenas
- Unidad de Tumores Sólidos Infantiles, Instituto de Investigación de Enfermedades Raras (IIER), Instituto de Salud Carlos III (ISCIII), 28220 Madrid, Spain; (S.T.C.); (C.R.-M.); (E.F.-T.); (R.M.M.-F.d.M.); (M.I.-M.); (J.A.-C.); (L.G.-G.); (L.G.-G.)
| | - Laura García-García
- Unidad de Tumores Sólidos Infantiles, Instituto de Investigación de Enfermedades Raras (IIER), Instituto de Salud Carlos III (ISCIII), 28220 Madrid, Spain; (S.T.C.); (C.R.-M.); (E.F.-T.); (R.M.M.-F.d.M.); (M.I.-M.); (J.A.-C.); (L.G.-G.); (L.G.-G.)
| | - Laura González-González
- Unidad de Tumores Sólidos Infantiles, Instituto de Investigación de Enfermedades Raras (IIER), Instituto de Salud Carlos III (ISCIII), 28220 Madrid, Spain; (S.T.C.); (C.R.-M.); (E.F.-T.); (R.M.M.-F.d.M.); (M.I.-M.); (J.A.-C.); (L.G.-G.); (L.G.-G.)
| | - Miguel Angel Moreno-Pelayo
- Servicio de Genética, Hospital Universitario Ramón y Cajal, IRYCIS, Carretera de Colmenar km 9.100, 28034 Madrid, Spain; (M.M.); (S.F.-P.); (M.A.M.-P.)
- Centro de Investigación Biomédica en Red de Enfermedades Raras, Instituto de Salud Carlos III (CB06/07/0048; CIBERER-ISCIII), 28029 Madrid, Spain
| | - Javier Alonso
- Unidad de Tumores Sólidos Infantiles, Instituto de Investigación de Enfermedades Raras (IIER), Instituto de Salud Carlos III (ISCIII), 28220 Madrid, Spain; (S.T.C.); (C.R.-M.); (E.F.-T.); (R.M.M.-F.d.M.); (M.I.-M.); (J.A.-C.); (L.G.-G.); (L.G.-G.)
- Centro de Investigación Biomédica en Red de Enfermedades Raras, Instituto de Salud Carlos III (CB06/07/1009; CIBERER-ISCIII), 28029 Madrid, Spain
- Correspondence:
| |
Collapse
|
7
|
Boone MA, Taslim C, Crow JC, Selich-Anderson J, Byrum AK, Showpnil IA, Sunkel BD, Wang M, Stanton BZ, Theisen ER, Lessnick SL. The FLI portion of EWS/FLI contributes a transcriptional regulatory function that is distinct and separable from its DNA-binding function in Ewing sarcoma. Oncogene 2021; 40:4759-4769. [PMID: 34145397 PMCID: PMC8298202 DOI: 10.1038/s41388-021-01876-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2020] [Revised: 05/19/2021] [Accepted: 05/28/2021] [Indexed: 02/05/2023]
Abstract
Ewing sarcoma is an aggressive bone cancer of children and young adults defined by the presence of a chromosomal translocation: t(11;22)(q24;q12). The encoded protein, EWS/FLI, fuses the amino-terminal domain of EWS to the carboxyl-terminus of FLI. The EWS portion is an intrinsically disordered transcriptional regulatory domain, while the FLI portion contains an ETS DNA-binding domain and two flanking regions of unknown function. Early studies using non-Ewing sarcoma models provided conflicting information on the roles of each domain of FLI in EWS/FLI oncogenic function. We therefore sought to define the specific contributions of each FLI domain to EWS/FLI activity in a well-validated Ewing sarcoma model and, in doing so, to better understand Ewing sarcoma development mediated by the fusion protein. We analyzed a series of engineered EWS/FLI mutants with alterations in the FLI portion using a variety of assays. Fluorescence anisotropy, CUT&RUN, and ATAC-sequencing experiments revealed that the isolated ETS domain is sufficient to maintain the normal DNA-binding and chromatin accessibility function of EWS/FLI. In contrast, RNA-sequencing and soft agar colony formation assays revealed that the ETS domain alone was insufficient for transcriptional regulatory and oncogenic transformation functions of the fusion protein. We found that an additional alpha-helix immediately downstream of the ETS domain is required for full transcriptional regulation and EWS/FLI-mediated oncogenesis. These data demonstrate a previously unknown role for FLI in transcriptional regulation that is distinct from its DNA-binding activity. This activity is critical for the cancer-causing function of EWS/FLI and may lead to novel therapeutic approaches.
Collapse
Affiliation(s)
- Megann A Boone
- Biomedical Sciences Graduate Program, The Ohio State University, Columbus, OH, USA
- Center for Childhood Cancer and Blood Diseases, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, OH, USA
| | - Cenny Taslim
- Center for Childhood Cancer and Blood Diseases, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, OH, USA
| | - Jesse C Crow
- Center for Childhood Cancer and Blood Diseases, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, OH, USA
| | - Julia Selich-Anderson
- Center for Childhood Cancer and Blood Diseases, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, OH, USA
| | - Andrea K Byrum
- Center for Childhood Cancer and Blood Diseases, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, OH, USA
| | - Iftekhar A Showpnil
- Center for Childhood Cancer and Blood Diseases, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, OH, USA
- Molecular, Cellular, and Developmental Biology Graduate Program, The Ohio State University, Columbus, OH, USA
| | - Benjamin D Sunkel
- Center for Childhood Cancer and Blood Diseases, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, OH, USA
| | - Meng Wang
- Center for Childhood Cancer and Blood Diseases, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, OH, USA
| | - Benjamin Z Stanton
- Biomedical Sciences Graduate Program, The Ohio State University, Columbus, OH, USA
- Center for Childhood Cancer and Blood Diseases, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, OH, USA
- Molecular, Cellular, and Developmental Biology Graduate Program, The Ohio State University, Columbus, OH, USA
- Department of Pediatrics, The Ohio State University, Columbus, OH, USA
| | - Emily R Theisen
- Biomedical Sciences Graduate Program, The Ohio State University, Columbus, OH, USA
- Center for Childhood Cancer and Blood Diseases, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, OH, USA
- Molecular, Cellular, and Developmental Biology Graduate Program, The Ohio State University, Columbus, OH, USA
- Department of Pediatrics, The Ohio State University, Columbus, OH, USA
| | - Stephen L Lessnick
- Biomedical Sciences Graduate Program, The Ohio State University, Columbus, OH, USA.
- Center for Childhood Cancer and Blood Diseases, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, OH, USA.
- Molecular, Cellular, and Developmental Biology Graduate Program, The Ohio State University, Columbus, OH, USA.
- Department of Pediatrics, The Ohio State University, Columbus, OH, USA.
| |
Collapse
|
8
|
Domenici G, Eduardo R, Castillo-Ecija H, Orive G, Montero Carcaboso Á, Brito C. PDX-Derived Ewing's Sarcoma Cells Retain High Viability and Disease Phenotype in Alginate Encapsulated Spheroid Cultures. Cancers (Basel) 2021; 13:cancers13040879. [PMID: 33669730 PMCID: PMC7922076 DOI: 10.3390/cancers13040879] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Revised: 01/29/2021] [Accepted: 02/15/2021] [Indexed: 12/17/2022] Open
Abstract
Simple Summary Ewing’s Sarcoma (ES) is the second most frequent bone tumour in children and young adults, with very aggressive behaviour and significant disease recurrence. To better study the disease and find new therapies, experimental models are needed. Recently, patient-derived xenografts (PDX), obtained by implanting patient tumour samples in immunodeficient mice, have been developed. However, when ES cells are extracted from the patient’s tumour or from PDX and placed on plasticware surfaces, they lose their original 3D configuration, cell identity and function. To overcome these issues, we implemented cultures of PDX-derived ES cells, by making them aggregate to form ES cell spheroids and then encapsulating these 3D spheroids into a hydrogel, alginate, to stabilize the culture. We show that this methodology maintained ES cell viability and intrinsic characteristics of the original ES tumour cells for at least one month and that it is suitable for study the effect of anticancer drugs. Abstract Ewing’s Sarcoma (ES) is the second most frequent malignant bone tumour in children and young adults and currently only untargeted chemotherapeutic approaches and surgery are available as treatment, although clinical trials are on-going for recently developed ES-targeted therapies. To study ES pathobiology and develop novel drugs, established cell lines and patient-derived xenografts (PDX) are the most employed experimental models. Nevertheless, the establishment of ES cell lines is difficult and the extensive use of PDX raises economic/ethical concerns. There is a growing consensus regarding the use of 3D cell culture to recapitulate physiological and pathophysiological features of human tissues, including drug sensitivity. Herein, we implemented a 3D cell culture methodology based on encapsulation of PDX-derived ES cell spheroids in alginate and maintenance in agitation-based culture systems. Under these conditions, ES cells displayed high proliferative and metabolic activity, while retaining the typical EWSR1-FLI1 chromosomal translocation. Importantly, 3D cultures presented reduced mouse PDX cell contamination compared to 2D cultures. Finally, we show that these 3D cultures can be employed in drug sensitivity assays, with results similar to those reported for the PDX of origin. In conclusion, this novel 3D cell culture method involving ES-PDX-derived cells is a suitable model to study ES pathobiology and can assist in the development of novel drugs against this disease, complementing PDX studies.
Collapse
Affiliation(s)
- Giacomo Domenici
- iBET, Instituto de Biologia Experimental e Tecnológica, Apartado 12, 2781-901 Oeiras, Portugal; (G.D.); (R.E.)
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da República, 2780-157 Oeiras, Portugal
| | - Rodrigo Eduardo
- iBET, Instituto de Biologia Experimental e Tecnológica, Apartado 12, 2781-901 Oeiras, Portugal; (G.D.); (R.E.)
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da República, 2780-157 Oeiras, Portugal
| | - Helena Castillo-Ecija
- Pediatric Hematology and Oncology, Hospital Sant Joan de Deu, Institut de Recerca Sant Joan de Déu, Passeig Sant Joan de Déu 2, 08950 Barcelona, Spain; (H.C.-E.); (Á.M.C.)
| | - Gorka Orive
- NanoBioCel Group, Laboratory of Pharmaceutics, School of Pharmacy, University of the Basque Country UPV/EHU, Paseo de la Universidad 7, 01006 Vitoria-Gasteiz, Spain;
- Biomedical Research Networking Centre in Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Paseo de la Universidad 7, 01006 Vitoria-Gasteiz, Spain
| | - Ángel Montero Carcaboso
- Pediatric Hematology and Oncology, Hospital Sant Joan de Deu, Institut de Recerca Sant Joan de Déu, Passeig Sant Joan de Déu 2, 08950 Barcelona, Spain; (H.C.-E.); (Á.M.C.)
| | - Catarina Brito
- iBET, Instituto de Biologia Experimental e Tecnológica, Apartado 12, 2781-901 Oeiras, Portugal; (G.D.); (R.E.)
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da República, 2780-157 Oeiras, Portugal
- Correspondence:
| |
Collapse
|
9
|
García-Domínguez DJ, Hontecillas-Prieto L, León EA, Sánchez-Molina S, Rodríguez-Núñez P, Morón FJ, Hajji N, Mackintosh C, de Álava E. An inducible ectopic expression system of EWSR1-FLI1 as a tool for understanding Ewing sarcoma oncogenesis. PLoS One 2020; 15:e0234243. [PMID: 32502203 PMCID: PMC7274397 DOI: 10.1371/journal.pone.0234243] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2019] [Accepted: 05/21/2020] [Indexed: 12/12/2022] Open
Abstract
The presence of the chimeric EWSR1-FLI1 oncoprotein is the main and initiating event defining Ewing sarcoma (ES). The dysregulation of epigenomic and proteomic homeostasis induced by the oncoprotein contributes to a wide variety of events involved in oncogenesis and tumor progression. Attempts at studying the effects of EWSR1-FLI1 in non-tumor cells to understand the mechanisms underlying sarcomagenesis have been unsuccessful to date, as ectopic expression of EWSR1-FLI1 blocks cell cycle progression and induces apoptosis in the tested cell lines. Therefore, it is essential to find a permissive cell type for EWSR1-FLI1 expression that allows its endogenous molecular functions to be studied. Here we have demonstrated that HeLa cell lines are permissive to EWSR1-FLI1 ectopic expression, and that our model substantially recapitulates the endogenous activity of the EWSR1-FLI1 fusion protein. This model could contribute to better understanding ES sarcomagenesis by helping to understand the molecular mechanisms induced by the EWSR1-FLI1 oncoprotein.
Collapse
Affiliation(s)
- Daniel J. García-Domínguez
- Institute of Biomedicine of Seville (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla/CIBERONC, Seville, Spain
- * E-mail: (DJGD); (EDA)
| | - Lourdes Hontecillas-Prieto
- Institute of Biomedicine of Seville (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla/CIBERONC, Seville, Spain
| | - Eduardo Andrés León
- Bioinformatics Unit, Instituto de Parasitología y Biomedicina “López-Neyra”, Consejo Superior de Investigaciones Científicas (IPBLN-CSIC), Granada, Spain
| | - Sara Sánchez-Molina
- Developmental Tumor Biology Laboratory, Institut de Recerca Pediàtrica—Hospital Sant Joan de Déu, Esplugues de Llobregat, Barcelona, Spain
| | - Pablo Rodríguez-Núñez
- Institute of Biomedicine of Seville (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla/CIBERONC, Seville, Spain
| | - Francisco J. Morón
- Genomics Core Facility, Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/Consejo Superior de Investigaciones Científicas/Universidad de Sevilla, Sevilla, Spain
| | - Nabil Hajji
- Division of Brain Sciences, The John Fulcher Molecular Neuro-Oncology Laboratory, Imperial College London, London, England, United Kingdom
| | | | - Enrique de Álava
- Institute of Biomedicine of Seville (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla/CIBERONC, Seville, Spain
- Department of Normal and Pathological Cytology and Histology, School of Medicine, University of Seville, Seville, Spain
- * E-mail: (DJGD); (EDA)
| |
Collapse
|
10
|
Flores G, Everett JH, Boguslawski EA, Oswald BM, Madaj ZB, Beddows I, Dikalov S, Adams M, Klumpp-Thomas CA, Kitchen-Goosen SM, Martin SE, Caplen NJ, Helman LJ, Grohar PJ. CDK9 Blockade Exploits Context-dependent Transcriptional Changes to Improve Activity and Limit Toxicity of Mithramycin for Ewing Sarcoma. Mol Cancer Ther 2020; 19:1183-1196. [PMID: 32127464 DOI: 10.1158/1535-7163.mct-19-0775] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Revised: 12/17/2019] [Accepted: 02/19/2020] [Indexed: 11/16/2022]
Abstract
There is a need to develop novel approaches to improve the balance between efficacy and toxicity for transcription factor-targeted therapies. In this study, we exploit context-dependent differences in RNA polymerase II processivity as an approach to improve the activity and limit the toxicity of the EWS-FLI1-targeted small molecule, mithramycin, for Ewing sarcoma. The clinical activity of mithramycin for Ewing sarcoma is limited by off-target liver toxicity that restricts the serum concentration to levels insufficient to inhibit EWS-FLI1. In this study, we perform an siRNA screen of the druggable genome followed by a matrix drug screen to identify mithramycin potentiators and a synergistic "class" effect with cyclin-dependent kinase 9 (CDK9) inhibitors. These CDK9 inhibitors enhanced the mithramycin-mediated suppression of the EWS-FLI1 transcriptional program leading to a shift in the IC50 and striking regressions of Ewing sarcoma xenografts. To determine whether these compounds may also be liver protective, we performed a qPCR screen of all known liver toxicity genes in HepG2 cells to identify mithramycin-driven transcriptional changes that contribute to the liver toxicity. Mithramycin induces expression of the BTG2 gene in HepG2 but not Ewing sarcoma cells, which leads to a liver-specific accumulation of reactive oxygen species (ROS). siRNA silencing of BTG2 rescues the induction of ROS and the cytotoxicity of mithramycin in these cells. Furthermore, CDK9 inhibition blocked the induction of BTG2 to limit cytotoxicity in HepG2, but not Ewing sarcoma cells. These studies provide the basis for a synergistic and less toxic EWS-FLI1-targeted combination therapy for Ewing sarcoma.
Collapse
Affiliation(s)
- Guillermo Flores
- Center for Cancer and Cell Biology, Van Andel Research Institute, Grand Rapids, Michigan.,College of Human Medicine, Michigan State University, Grand Rapids, Michigan
| | - Joel H Everett
- Department of Pharmacology, Vanderbilt University, Nashville, Tennessee
| | - Elissa A Boguslawski
- Center for Cancer and Cell Biology, Van Andel Research Institute, Grand Rapids, Michigan
| | - Brandon M Oswald
- Center for Cancer and Cell Biology, Van Andel Research Institute, Grand Rapids, Michigan
| | - Zachary B Madaj
- Bioinformatics and Biostatistics Core, Van Andel Research Institute, Grand Rapids, Michigan
| | - Ian Beddows
- Bioinformatics and Biostatistics Core, Van Andel Research Institute, Grand Rapids, Michigan
| | - Sergey Dikalov
- The Free Radicals in Medicine Core, Division of Clinical Pharmacology Vanderbilt University Medical Center, Nashville, Tennessee
| | - Marie Adams
- Bioinformatics and Biostatistics Core, Van Andel Research Institute, Grand Rapids, Michigan
| | - Carleen A Klumpp-Thomas
- Trans-NIH RNAi Screening Facility, Division of Preclinical Innovation, National Center for Advancing Translational Sciences, NIH, Rockville, Maryland
| | - Susan M Kitchen-Goosen
- Center for Cancer and Cell Biology, Van Andel Research Institute, Grand Rapids, Michigan
| | - Scott E Martin
- Trans-NIH RNAi Screening Facility, Division of Preclinical Innovation, National Center for Advancing Translational Sciences, NIH, Rockville, Maryland
| | - Natasha J Caplen
- Genetics Branch, Center for Cancer Research, NCI, Bethesda, Maryland
| | - Lee J Helman
- Pediatric Oncology Branch, Center for Cancer Research, NCI, Bethesda, Maryland
| | - Patrick J Grohar
- Center for Cancer and Cell Biology, Van Andel Research Institute, Grand Rapids, Michigan. .,Pediatric Oncology Branch, Center for Cancer Research, NCI, Bethesda, Maryland.,Department of Pediatrics, Vanderbilt University, Nashville, Tennessee.,Department of Pediatrics and Human Development, Michigan State University, Grand Rapids, Michigan.,Division of Pediatric Hematology-Oncology, Helen DeVos Children's Hospital, Grand Rapids, Michigan.,Division of Oncology, Children's Hospital of Philadelphia, Philadelphia, PA
| |
Collapse
|
11
|
Sen N, Cross AM, Lorenzi PL, Khan J, Gryder BE, Kim S, Caplen NJ. EWS-FLI1 reprograms the metabolism of Ewing sarcoma cells via positive regulation of glutamine import and serine-glycine biosynthesis. Mol Carcinog 2018; 57:1342-1357. [PMID: 29873416 PMCID: PMC6175245 DOI: 10.1002/mc.22849] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Revised: 05/22/2018] [Accepted: 06/01/2018] [Indexed: 12/12/2022]
Abstract
Ewing sarcoma (EWS) is a soft tissue and bone tumor that occurs primarily in adolescents and young adults. In most cases of EWS, the chimeric transcription factor, EWS-FLI1 is the primary oncogenic driver. The epigenome of EWS cells reflects EWS-FLI1 binding and activation or repression of transcription. Here, we demonstrate that EWS-FLI1 positively regulates the expression of proteins required for serine-glycine biosynthesis and uptake of the alternative nutrient source glutamine. Specifically, we show that EWS-FLI1 activates expression of PHGDH, PSAT1, PSPH, and SHMT2. Using cell-based studies, we also establish that EWS cells are dependent on glutamine for cell survival and that EWS-FLI1 positively regulates expression of the glutamine transporter, SLC1A5 and two enzymes involved in the one-carbon cycle, MTHFD2 and MTHFD1L. Inhibition of serine-glycine biosynthesis in EWS cells impacts their redox state leading to an accumulation of reactive oxygen species, DNA damage, and apoptosis. Importantly, analysis of EWS primary tumor transcriptome data confirmed that the aforementioned genes we identified as regulated by EWS-FLI1 exhibit increased expression compared with normal tissues. Furthermore, retrospective analysis of an independent data set generated a significant stratification of the overall survival of EWS patients into low- and high-risk groups based on the expression of PHGDH, PSAT1, PSPH, SHMT2, SLC1A5, MTHFD2, and MTHFD1L. In summary, our study demonstrates that EWS-FLI1 reprograms the metabolism of EWS cells and that serine-glycine metabolism or glutamine uptake are potential targetable vulnerabilities in this tumor type.
Collapse
Affiliation(s)
- Nirmalya Sen
- Functional Genetics Section, Genetics Branch, Center for Cancer Research (CCR)National Cancer Institute (NCI)BethesdaMaryland
| | - Allison M. Cross
- Functional Genetics Section, Genetics Branch, Center for Cancer Research (CCR)National Cancer Institute (NCI)BethesdaMaryland
| | - Philip L. Lorenzi
- Proteomic and Metabolomics Core Facility, Department of Bioinformatics and Computational BiologyThe University of Texas MD Anderson Cancer CenterHoustonTexas
| | - Javed Khan
- Oncogenomics Section, Genetics Branch, Center for Cancer Research (CCR)National Cancer Institute (NCI)BethesdaMaryland
| | - Berkley E. Gryder
- Oncogenomics Section, Genetics Branch, Center for Cancer Research (CCR)National Cancer Institute (NCI)BethesdaMaryland
| | - Suntae Kim
- Functional Genetics Section, Genetics Branch, Center for Cancer Research (CCR)National Cancer Institute (NCI)BethesdaMaryland
| | - Natasha J. Caplen
- Functional Genetics Section, Genetics Branch, Center for Cancer Research (CCR)National Cancer Institute (NCI)BethesdaMaryland
| |
Collapse
|
12
|
Bulbul A, Shen JP, Xiu J, Tamayo P, Husain H. Genomic and Proteomic Alterations in Desmoplastic Small Round Blue-Cell Tumors. JCO Precis Oncol 2018; 2:1700170. [PMID: 32913982 DOI: 10.1200/po.17.00170] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Purpose Desmoplastic small round blue-cell tumors (DSRCTs) are sarcomas that contain the t(11;22) (p13;q12) translocation EWS-WT1 fusion protein. Because this is a rare tumor type, prospective clinical trials in DSRCT are challenging. Patients are treated in a manner similar to those with Ewing sarcoma; however, differences in prognosis and clinical presentation suggest fundamental differences in biology and potentially different therapeutic implications. This study aimed to characterize the molecular characteristics of DSRCT tumors to explore unique therapeutic options for this extremely rare and aggressive cancer type. Methods Thirty-five DSRCT tumors were assessed using next-generation sequencing, protein expression (immunohistochemistry), and gene amplification (chromogenic in situ hybridization or fluorescence in situ hybridization). Three patients had tumor mutational load, which was calculated as somatic nonsynonymous missense mutations sequenced with a 592-gene panel. Gene expression data were obtained for an additional seven DSRCT tumors. Molecular alterations were compared with 88 Ewing sarcomas. Results The most common alterations that distinguished DSRCTs from Ewing sarcoma included higher androgen receptor (AR), TUBB3, epidermal growth factor receptor, and TOPO2A expression. Independent analysis by RNA sequencing confirmed higher AR expression from an independent data set of EWS-WT1 fusion-positive DSRCTs compared with Ewing sarcoma and a pan-cancer analysis. DSRCTs had somatic mutations that were identified in TP53 and FOXO3, averaged five mutations per megabase, and no programmed death-ligand 1 expression was detected in any DSRCT samples. Conclusion The current analysis provides the first comparative analysis, to our knowledge, of molecular aberrations that distinguish DSRCT from Ewing sarcoma. High AR expression seems to be a defining event in these malignancies, and additional investigation of the responsiveness of AR inhibitors in this disease is encouraged.
Collapse
Affiliation(s)
- Ajaz Bulbul
- , , , and , University of California San Diego, La Jolla, CA; and , Caris Life Sciences, Phoenix, AZ
| | - John Paul Shen
- , , , and , University of California San Diego, La Jolla, CA; and , Caris Life Sciences, Phoenix, AZ
| | - Joanne Xiu
- , , , and , University of California San Diego, La Jolla, CA; and , Caris Life Sciences, Phoenix, AZ
| | - Pablo Tamayo
- , , , and , University of California San Diego, La Jolla, CA; and , Caris Life Sciences, Phoenix, AZ
| | - Hatim Husain
- , , , and , University of California San Diego, La Jolla, CA; and , Caris Life Sciences, Phoenix, AZ
| |
Collapse
|
13
|
Liu XF, Li XY, Zheng PS, Yang WT. DAX1 promotes cervical cancer cell growth and tumorigenicity through activation of Wnt/β-catenin pathway via GSK3β. Cell Death Dis 2018; 9:339. [PMID: 29497051 PMCID: PMC5832878 DOI: 10.1038/s41419-018-0359-6] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Revised: 01/08/2018] [Accepted: 01/10/2018] [Indexed: 01/20/2023]
Abstract
DAX1 is well known for its fundamental role in several types of cancer, while its biological role in cervical cancer remains largely unexplored. The expression of DAX1 in cervical carcinoma tissue was examined using immunohistochemistry and western blot. The effects of DAX1 silencing on the cell growth, tumor formation, and CSC (cancer stem cell) characteristics were also investigated. DAX1 expressed a gradual increase from normal cervix to high-grade squamous intraepithelial lesions, and consequently to cervical cancer. Silence of DAX1 significantly inhibited the cell growth, tumorigenicity, and tumorsphere formation. Furthermore, the TOP/FOP-Flash reporter assay revealed that Wnt/β-catenin pathway was significantly inactivated in DAX1-silenced cervical cancer cells with the downregulation of Wnt/β-catenin targeting genes, including cyclinD1 and c-myc. Moreover, dual-luciferase reporter and chromatin immunoprecipitation (ChIP) assay confirmed that DAX1 transcriptionally repressed glycogen synthase kinase 3β (GSK3β), an inhibitor of the Wnt/β-catenin pathway, by physically interacting with -666~-444 motif on the GSK3β promoter. Additionally, the blockage of GSK3β by CHIR-99021 resulted in a significant increase of CSC characteristics induced by the silence of DAX1. Our data demonstrated that DAX1 is overexpressed in cervical cancer, and that it promotes cell growth and tumorigenicity through activating Wnt/β-catenin pathway mediated by GSK3β.
Collapse
Affiliation(s)
- Xiao-Fang Liu
- Department of Reproductive Medicine, The First Affiliated Hospital of Xi'an Jiaotong University, 710061, Xi'an, Shaanxi, China
| | - Xue-Yuan Li
- Department of Reproductive Medicine, The First Affiliated Hospital of Xi'an Jiaotong University, 710061, Xi'an, Shaanxi, China
| | - Peng-Sheng Zheng
- Department of Reproductive Medicine, The First Affiliated Hospital of Xi'an Jiaotong University, 710061, Xi'an, Shaanxi, China.
- Key Laboratory of Environment and Genes Related to Diseases, Ministry of Education of the People's Republic of China, 710061, Xi'an, Shaanxi, China.
| | - Wen-Ting Yang
- Department of Reproductive Medicine, The First Affiliated Hospital of Xi'an Jiaotong University, 710061, Xi'an, Shaanxi, China.
| |
Collapse
|
14
|
Yu H, Ge Y, Guo L, Huang L. Potential approaches to the treatment of Ewing's sarcoma. Oncotarget 2018; 8:5523-5539. [PMID: 27740934 PMCID: PMC5354928 DOI: 10.18632/oncotarget.12566] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Accepted: 10/03/2016] [Indexed: 01/04/2023] Open
Abstract
Ewing’s sarcoma (ES) is a highly aggressive and metastatic tumor in children and young adults caused by a chromosomal fusion between the Ewing sarcoma breakpoint region 1 (EWSR1) gene and the transcription factor FLI1 gene. ES is managed with standard treatments, including chemotherapy, surgery and radiation. Although the 5-year survival rate for primary ES has improved, the survival rate for ES patients with metastases or recurrence remains low. Several novel molecular targets in ES have recently been identified and investigated in preclinical and clinical settings, and targeting the function of receptor tyrosine kinases (RTKs), the fusion protein EWS-FLI1 and mTOR has shown promise. There has also been increasing interest in the immune responses of ES patients. Immunotherapies using T cells, NK cells, cancer vaccines and monoclonal antibodies have been considered for ES, especially for recurrent patients. Because understanding the pathogenesis of ES is extremely important for the development of novel treatments, this review focuses on the mechanisms and functions of targeted therapies and immunotherapies in ES. It is anticipated that integrating the knowledge obtained from basic research and translational and clinical studies will lead to the development of novel therapeutic strategies for the treatment of ES.
Collapse
Affiliation(s)
- Hongjiu Yu
- Department of Pathophysiology, Dalian Medical University, Dalian, Liaoning, P.R. China.,Department of VIP, The First Affiliated Hospital, Dalian Medical University, Dalian, Liaoning, P.R. China
| | - Yonggui Ge
- Department of Pathophysiology, Dalian Medical University, Dalian, Liaoning, P.R. China
| | - Lianying Guo
- Department of Pathophysiology, Dalian Medical University, Dalian, Liaoning, P.R. China
| | - Lin Huang
- Department of Pathophysiology, Dalian Medical University, Dalian, Liaoning, P.R. China
| |
Collapse
|
15
|
Jacques C, Lamoureux F, Baud'huin M, Rodriguez Calleja L, Quillard T, Amiaud J, Tirode F, Rédini F, Bradner JE, Heymann D, Ory B. Targeting the epigenetic readers in Ewing sarcoma inhibits the oncogenic transcription factor EWS/Fli1. Oncotarget 2018; 7:24125-40. [PMID: 27006472 PMCID: PMC5029689 DOI: 10.18632/oncotarget.8214] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Accepted: 03/02/2016] [Indexed: 11/25/2022] Open
Abstract
Ewing Sarcoma is a rare bone and soft tissue malignancy affecting children and young adults. Chromosomal translocations in this cancer produce fusion oncogenes as characteristic molecular signatures of the disease. The most common case is the translocation t (11; 22) (q24;q12) which yields the EWS-Fli1 chimeric transcription factor. Finding a way to directly target EWS-Fli1 remains a central therapeutic approach to eradicate this aggressive cancer. Here we demonstrate that treating Ewing Sarcoma cells with JQ1(+), a BET bromodomain inhibitor, represses directly EWS-Fli1 transcription as well as its transcriptional program. Moreover, the Chromatin Immuno Precipitation experiments demonstrate for the first time that these results are a consequence of the depletion of BRD4, one of the BET bromodomains protein from the EWS-Fli1 promoter. In vitro, JQ1(+) treatment reduces the cell viability, impairs the cell clonogenic and the migratory abilities, and induces a G1-phase blockage as well as a time- and a dose-dependent apoptosis. Furthermore, in our in vivo model, we observed a tumor burden delay, an inhibition of the global vascularization and an increase of the mice overall survival. Taken together, our data indicate that inhibiting the BET bromodomains interferes with EWS-FLi1 transcription and could be a promising strategy in the Ewing tumors context.
Collapse
Affiliation(s)
- Camille Jacques
- INSERM, UMR 957, Équipe Labellisée Ligue 2012, Nantes, France.,Physiopathologie de la Résorption Osseuse et Thérapie des Tumeurs Osseuses Primitives, Université de Nantes, Nantes Atlantique Universités, EA3822, Nantes, France
| | - François Lamoureux
- INSERM, UMR 957, Équipe Labellisée Ligue 2012, Nantes, France.,Physiopathologie de la Résorption Osseuse et Thérapie des Tumeurs Osseuses Primitives, Université de Nantes, Nantes Atlantique Universités, EA3822, Nantes, France
| | - Marc Baud'huin
- INSERM, UMR 957, Équipe Labellisée Ligue 2012, Nantes, France.,Physiopathologie de la Résorption Osseuse et Thérapie des Tumeurs Osseuses Primitives, Université de Nantes, Nantes Atlantique Universités, EA3822, Nantes, France.,Nantes University Hospital, Nantes, France
| | - Lidia Rodriguez Calleja
- INSERM, UMR 957, Équipe Labellisée Ligue 2012, Nantes, France.,Physiopathologie de la Résorption Osseuse et Thérapie des Tumeurs Osseuses Primitives, Université de Nantes, Nantes Atlantique Universités, EA3822, Nantes, France
| | - Thibaut Quillard
- INSERM, UMR 957, Équipe Labellisée Ligue 2012, Nantes, France.,Physiopathologie de la Résorption Osseuse et Thérapie des Tumeurs Osseuses Primitives, Université de Nantes, Nantes Atlantique Universités, EA3822, Nantes, France
| | - Jérôme Amiaud
- INSERM, UMR 957, Équipe Labellisée Ligue 2012, Nantes, France.,Physiopathologie de la Résorption Osseuse et Thérapie des Tumeurs Osseuses Primitives, Université de Nantes, Nantes Atlantique Universités, EA3822, Nantes, France
| | | | - Françoise Rédini
- INSERM, UMR 957, Équipe Labellisée Ligue 2012, Nantes, France.,Physiopathologie de la Résorption Osseuse et Thérapie des Tumeurs Osseuses Primitives, Université de Nantes, Nantes Atlantique Universités, EA3822, Nantes, France
| | - James E Bradner
- Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts, USA.,Department of Medicine, Harvard Medical School, Boston, Massachusetts, USA
| | - Dominique Heymann
- INSERM, UMR 957, Équipe Labellisée Ligue 2012, Nantes, France.,Physiopathologie de la Résorption Osseuse et Thérapie des Tumeurs Osseuses Primitives, Université de Nantes, Nantes Atlantique Universités, EA3822, Nantes, France.,Nantes University Hospital, Nantes, France
| | - Benjamin Ory
- INSERM, UMR 957, Équipe Labellisée Ligue 2012, Nantes, France.,Physiopathologie de la Résorption Osseuse et Thérapie des Tumeurs Osseuses Primitives, Université de Nantes, Nantes Atlantique Universités, EA3822, Nantes, France
| |
Collapse
|
16
|
Lu Y, Liu Y, Liao S, Tu W, Shen Y, Yan Y, Tao D, Lu Y, Ma Y, Yang Y, Zhang S. Epigenetic modifications promote the expression of the orphan nuclear receptor NR0B1 in human lung adenocarcinoma cells. Oncotarget 2017; 7:43162-43176. [PMID: 27281610 PMCID: PMC5190015 DOI: 10.18632/oncotarget.9012] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Accepted: 04/15/2016] [Indexed: 02/05/2023] Open
Abstract
The ectopic activation of NR0B1 is involved in the development of some cancers. However, the regulatory mechanisms controlling NR0B1 expression are not well understood. Therefore, the epigenetic modifications promoting NR0B1 activation were examined in this study. NR0B1 protein was detected in cancerous tissues of more than 50% of human lung adenocarcinoma (ADCA) cases and tended to be expressed in low-differentiated cancerous tissues obtained from males. Nevertheless, NR0B1 activation in ADCA has not previously been correlated with DNA demethylation. NR0B1 expression was not detected in 293T cells, although it contains a hypomethylated NR0B1 promoter. Treating 293T cells with a histone deacetylase inhibitor increased acetylated histone H4 binding to the NR0B1 promoter and activated NR0B1 expression. In contrast, treatment with histone methylase inhibitors decreased the methylation of histones H3K9 and H3K27 and slightly induced NR0B1 transcription. Furthermore, the level of acetyl-histone H4 binding to the NR0B1 promoter increased, whereas the occupancy of H3K27me3 was lower in cancerous tissues than in non-cancerous tissues. Similar histone occupancies were confirmed in a comparison of cancerous tissues with strong, moderate and negative NR0B1 expression. In conclusion, this study shows that CpG methylation within the NR0B1 promoter is not involved in the in vivo regulation of NR0B1 expression, whereas the hyperacetylation of histone H4 and the unmethylation of histones H3K9 and H3K27, and their binding to the NR0B1 promoter results in decondensed euchromatin for NR0B1 activation.
Collapse
Affiliation(s)
- Yongjie Lu
- Department of Medical Genetics and Division of Human Morbid Genomics, State Key Laboratory of Biotherapy, West China Hospital, West China Medical School, Sichuan University, Chengdu, Sichuan Province, China
| | - Yunqiang Liu
- Department of Medical Genetics and Division of Human Morbid Genomics, State Key Laboratory of Biotherapy, West China Hospital, West China Medical School, Sichuan University, Chengdu, Sichuan Province, China
| | - Shunyao Liao
- Diabetic Center and Institute of Transplantation, Sichuan Academy of Medical Science & Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan Province, China
| | - Wenling Tu
- Department of Medical Genetics and Division of Human Morbid Genomics, State Key Laboratory of Biotherapy, West China Hospital, West China Medical School, Sichuan University, Chengdu, Sichuan Province, China
| | - Ying Shen
- Department of Medical Genetics and Division of Human Morbid Genomics, State Key Laboratory of Biotherapy, West China Hospital, West China Medical School, Sichuan University, Chengdu, Sichuan Province, China
| | - Yuanlong Yan
- Department of Medical Genetics and Division of Human Morbid Genomics, State Key Laboratory of Biotherapy, West China Hospital, West China Medical School, Sichuan University, Chengdu, Sichuan Province, China
| | - Dachang Tao
- Department of Medical Genetics and Division of Human Morbid Genomics, State Key Laboratory of Biotherapy, West China Hospital, West China Medical School, Sichuan University, Chengdu, Sichuan Province, China
| | - Yilu Lu
- Department of Medical Genetics and Division of Human Morbid Genomics, State Key Laboratory of Biotherapy, West China Hospital, West China Medical School, Sichuan University, Chengdu, Sichuan Province, China
| | - Yongxin Ma
- Department of Medical Genetics and Division of Human Morbid Genomics, State Key Laboratory of Biotherapy, West China Hospital, West China Medical School, Sichuan University, Chengdu, Sichuan Province, China
| | - Yuan Yang
- Department of Medical Genetics and Division of Human Morbid Genomics, State Key Laboratory of Biotherapy, West China Hospital, West China Medical School, Sichuan University, Chengdu, Sichuan Province, China
| | - Sizhong Zhang
- Department of Medical Genetics and Division of Human Morbid Genomics, State Key Laboratory of Biotherapy, West China Hospital, West China Medical School, Sichuan University, Chengdu, Sichuan Province, China
| |
Collapse
|
17
|
Grohar PJ, Glod J, Peer CJ, Sissung TM, Arnaldez FI, Long L, Figg WD, Whitcomb P, Helman LJ, Widemann BC. A phase I/II trial and pharmacokinetic study of mithramycin in children and adults with refractory Ewing sarcoma and EWS-FLI1 fusion transcript. Cancer Chemother Pharmacol 2017; 80:645-652. [PMID: 28735378 DOI: 10.1007/s00280-017-3382-x] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Accepted: 06/30/2017] [Indexed: 12/20/2022]
Abstract
PURPOSE In a preclinical drug screen, mithramycin was identified as a potent inhibitor of the Ewing sarcoma EWS-FLI1 transcription factor. We conducted a phase I/II trial to determine the dose-limiting toxicities (DLT), maximum tolerated dose (MTD), and pharmacokinetics (PK) of mithramycin in children with refractory solid tumors, and the activity in children and adults with refractory Ewing sarcoma. PATIENTS AND METHODS Mithramycin was administered intravenously over 6 h once daily for 7 days for 28 day cycles. Adult patients (phase II) initially received mithramycin at the previously determined recommended dose of 25 µg/kg/dose. The planned starting dose for children (phase I) was 17.5 µg/kg/dose. Plasma samples were obtained for mithramycin PK analysis. RESULTS The first two adult patients experienced reversible grade 4 alanine aminotransferase (ALT)/aspartate aminotransferase (AST) elevation exceeding the MTD. Subsequent adult patients received mithramycin at 17.5 µg/kg/dose, and children at 13 µg/kg/dose with dexamethasone pretreatment. None of the four subsequent adult and two pediatric patients experienced cycle 1 DLT. No clinical responses were observed. The average maximal mithramycin plasma concentration in four patients was 17.8 ± 4.6 ng/mL. This is substantially below the sustained mithramycin concentrations ≥50 nmol/L required to suppress EWS-FLI1 transcriptional activity in preclinical studies. Due to inability to safely achieve the desired mithramycin exposure, the trial was closed to enrollment. CONCLUSIONS Hepatotoxicity precluded the administration of a mithramycin at a dose required to inhibit EWS-FLI1. Evaluation of mithramycin in patients selected for decreased susceptibility to elevated transaminases may allow for improved drug exposure.
Collapse
Affiliation(s)
- Patrick J Grohar
- Pediatric Oncology Branch, Center for Cancer Research, National Cancer Institute, Bethesda, MD, USA
- Department of Pediatrics, Van Andel Research Institute, Helen DeVos Children's Hospital, Michigan State University, East Lansing, USA
| | - John Glod
- Pediatric Oncology Branch, Center for Cancer Research, National Cancer Institute, Bethesda, MD, USA.
| | - Cody J Peer
- Clinical Pharmacology Program, National Cancer Institute, Bethesda, MD, USA
| | - Tristan M Sissung
- Department of Pediatrics, Van Andel Research Institute, Helen DeVos Children's Hospital, Michigan State University, East Lansing, USA
| | - Fernanda I Arnaldez
- Pediatric Oncology Branch, Center for Cancer Research, National Cancer Institute, Bethesda, MD, USA
| | - Lauren Long
- Pediatric Oncology Branch, Center for Cancer Research, National Cancer Institute, Bethesda, MD, USA
| | - William D Figg
- Clinical Pharmacology Program, National Cancer Institute, Bethesda, MD, USA
| | - Patricia Whitcomb
- Pediatric Oncology Branch, Center for Cancer Research, National Cancer Institute, Bethesda, MD, USA
| | - Lee J Helman
- Pediatric Oncology Branch, Center for Cancer Research, National Cancer Institute, Bethesda, MD, USA
| | - Brigitte C Widemann
- Pediatric Oncology Branch, Center for Cancer Research, National Cancer Institute, Bethesda, MD, USA
| |
Collapse
|
18
|
Spraggon L, Martelotto LG, Hmeljak J, Hitchman TD, Wang J, Wang L, Slotkin EK, Fan PD, Reis-Filho JS, Ladanyi M. Generation of conditional oncogenic chromosomal translocations using CRISPR-Cas9 genomic editing and homology-directed repair. J Pathol 2017; 242:102-112. [PMID: 28188619 DOI: 10.1002/path.4883] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Revised: 01/27/2017] [Accepted: 01/30/2017] [Indexed: 01/11/2023]
Abstract
Chromosomal rearrangements encoding oncogenic fusion proteins are found in a wide variety of malignancies. The use of programmable nucleases to generate specific double-strand breaks in endogenous loci, followed by non-homologous end joining DNA repair, has allowed several of these translocations to be generated as constitutively expressed fusion genes within a cell population. Here, we describe a novel approach that combines CRISPR-Cas9 technology with homology-directed repair to engineer, capture, and modulate the expression of chromosomal translocation products in a human cell line. We have applied this approach to the genetic modelling of t(11;22)(q24;q12) and t(11;22)(p13;q12), translocation products of the EWSR1 gene and its 3' fusion partners FLI1 and WT1, present in Ewing's sarcoma and desmoplastic small round cell tumour, respectively. Our innovative approach allows for temporal control of the expression of engineered endogenous chromosomal rearrangements, and provides a means to generate models to study tumours driven by fusion genes. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Collapse
Affiliation(s)
- Lee Spraggon
- Department of Pathology, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Luciano G Martelotto
- Department of Pathology, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Julija Hmeljak
- Department of Pathology, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Tyler D Hitchman
- Department of Pathology, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Jiang Wang
- Department of Pathology, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Lu Wang
- Department of Pathology, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Emily K Slotkin
- Department of Pediatrics, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Pang-Dian Fan
- Department of Pathology, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Jorge S Reis-Filho
- Department of Pathology, Memorial Sloan Kettering Cancer Center, New York, NY, USA.,Human Oncology and Pathogenesis Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Marc Ladanyi
- Department of Pathology, Memorial Sloan Kettering Cancer Center, New York, NY, USA.,Human Oncology and Pathogenesis Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| |
Collapse
|
19
|
He T, Surdez D, Rantala JK, Haapa-Paananen S, Ban J, Kauer M, Tomazou E, Fey V, Alonso J, Kovar H, Delattre O, Iljin K. High-throughput RNAi screen in Ewing sarcoma cells identifies leucine rich repeats and WD repeat domain containing 1 (LRWD1) as a regulator of EWS-FLI1 driven cell viability. Gene 2016; 596:137-146. [PMID: 27760381 DOI: 10.1016/j.gene.2016.10.021] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Revised: 09/21/2016] [Accepted: 10/14/2016] [Indexed: 12/31/2022]
Abstract
A translocation leading to the formation of an oncogenic EWS-ETS fusion protein defines Ewing sarcoma. The most frequent gene fusion, present in 85 percent of Ewing sarcomas, is EWS-FLI1. Here, a high-throughput RNA interference screen was performed to identify genes whose function is critical for EWS-FLI1 driven cell viability. In total, 6781 genes were targeted by siRNA molecules and the screen was performed both in presence and absence of doxycycline-inducible expression of the EWS-FLI1 shRNA in A673/TR/shEF Ewing sarcoma cells. The Leucine rich repeats and WD repeat Domain containing 1 (LRWD1) targeting siRNA pool was the strongest hit reducing cell viability only in EWS-FLI1 expressing Ewing sarcoma cells. LRWD1 had been previously described as a testis specific gene with only limited information on its function. Analysis of LRWD1 mRNA levels in patient samples indicated that high expression associated with poor overall survival in Ewing sarcoma. Gene ontology analysis of LRWD1 co-expressed genes in Ewing tumors revealed association with DNA replication and analysis of differentially expressed genes in LRWD1 depleted Ewing sarcoma cells indicated a role in connective tissue development and cellular morphogenesis. Moreover, EWS-FLI1 repressed genes with repressive H3K27me3 chromatin marks were highly enriched among LRWD1 target genes in A673/TR/shEF Ewing sarcoma cells, suggesting that LRWD1 contributes to EWS-FLI1 driven transcriptional regulation. Taken together, we have identified LRWD1 as a novel regulator of EWS-FLI1 driven cell viability in A673/TR/shEF Ewing sarcoma cells, shown association between high LRWD1 mRNA expression and aggressive disease and identified processes by which LRWD1 may promote oncogenesis in Ewing sarcoma.
Collapse
Affiliation(s)
- Tao He
- VTT Technical Research Centre of Finland, Turku, Finland
| | - Didier Surdez
- Institut Curie, Unité de génétique somatique, Paris, France; Genetics and Biology of Cancers Unit, Institut Curie, PSL Research University, Paris, France; INSERM U830, Institut Curie Research Center, Paris, France
| | | | | | - Jozef Ban
- Children's Cancer Research Institute, St. Anna Kinderkrebsforschung, Vienna, Austria
| | - Maximilian Kauer
- Children's Cancer Research Institute, St. Anna Kinderkrebsforschung, Vienna, Austria
| | - Eleni Tomazou
- Children's Cancer Research Institute, St. Anna Kinderkrebsforschung, Vienna, Austria
| | - Vidal Fey
- VTT Technical Research Centre of Finland, Turku, Finland
| | - Javier Alonso
- Unidad de Tumores Sólidos Infantiles, Área de Genética Humana, Instituto de Investigación de Enfermedades Raras, Instituto de Salud Carlos III, Madrid, Spain
| | - Heinrich Kovar
- Children's Cancer Research Institute, St. Anna Kinderkrebsforschung, Vienna, Austria; Department of Pediatrics, Medical University, Vienna, Austria
| | - Olivier Delattre
- Institut Curie, Unité de génétique somatique, Paris, France; Genetics and Biology of Cancers Unit, Institut Curie, PSL Research University, Paris, France; INSERM U830, Institut Curie Research Center, Paris, France; Institut Curie Genomics of Excellence (ICGex) Platform, Institut Curie Research Center, Paris, France
| | | |
Collapse
|
20
|
Harlow ML, Maloney N, Roland J, Guillen Navarro MJ, Easton MK, Kitchen-Goosen SM, Boguslawski EA, Madaj ZB, Johnson BK, Bowman MJ, D'Incalci M, Winn ME, Turner L, Hostetter G, Galmarini CM, Aviles PM, Grohar PJ. Lurbinectedin Inactivates the Ewing Sarcoma Oncoprotein EWS-FLI1 by Redistributing It within the Nucleus. Cancer Res 2016; 76:6657-6668. [PMID: 27697767 DOI: 10.1158/0008-5472.can-16-0568] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Revised: 08/31/2016] [Accepted: 09/05/2016] [Indexed: 12/17/2022]
Abstract
There is a great need to develop novel approaches to target oncogenic transcription factors with small molecules. Ewing sarcoma is emblematic of this need, as it depends on the continued activity of the EWS-FLI1 transcription factor to maintain the malignant phenotype. We have previously shown that the small molecule trabectedin interferes with EWS-FLI1. Here, we report important mechanistic advances and a second-generation inhibitor to provide insight into the therapeutic targeting of EWS-FLI1. We discovered that trabectedin functionally inactivated EWS-FLI1 by redistributing the protein within the nucleus to the nucleolus. This effect was rooted in the wild-type functions of the EWSR1, compromising the N-terminal half of the chimeric oncoprotein, which is known to be similarly redistributed within the nucleus in the presence of UV light damage. A second-generation trabectedin analogue lurbinectedin (PM01183) caused the same nuclear redistribution of EWS-FLI1, leading to a loss of activity at the promoter, mRNA, and protein levels of expression. Tumor xenograft studies confirmed this effect, and it was increased in combination with irinotecan, leading to tumor regression and replacement of Ewing sarcoma cells with benign fat cells. The net result of combined lurbinectedin and irinotecan treatment was a complete reversal of EWS-FLI1 activity and elimination of established tumors in 30% to 70% of mice after only 11 days of therapy. Our results illustrate the preclinical safety and efficacy of a disease-specific therapy targeting the central oncogenic driver in Ewing sarcoma. Cancer Res; 76(22); 6657-68. ©2016 AACR.
Collapse
Affiliation(s)
- Matt L Harlow
- Department of Cancer Biology, Vanderbilt University, Nashville, Tennessee
| | - Nichole Maloney
- Department of Pediatrics, Vanderbilt University, Nashville, Tennessee
| | - Joseph Roland
- Epithelial Biology Center, Vanderbilt University School of Medicine, Nashville, Tennessee
| | | | | | | | | | | | - Ben K Johnson
- Van Andel Research Institute, Grand Rapids, Michigan
| | | | | | - Mary E Winn
- Van Andel Research Institute, Grand Rapids, Michigan
| | - Lisa Turner
- Van Andel Research Institute, Grand Rapids, Michigan
| | | | | | | | - Patrick J Grohar
- Department of Pediatrics, Vanderbilt University, Nashville, Tennessee. .,Van Andel Research Institute, Grand Rapids, Michigan.,Helen De Vos Children's Hospital, Grand Rapids, Michigan.,Department of Pediatrics, Michigan State University, Grand Rapids, Michigan
| |
Collapse
|
21
|
Osgood CL, Maloney N, Kidd CG, Kitchen-Goosen S, Segars L, Gebregiorgis M, Woldemichael GM, He M, Sankar S, Lessnick SL, Kang M, Smith M, Turner L, Madaj ZB, Winn ME, Núñez LE, González-Sabín J, Helman LJ, Morís F, Grohar PJ. Identification of Mithramycin Analogues with Improved Targeting of the EWS-FLI1 Transcription Factor. Clin Cancer Res 2016; 22:4105-18. [PMID: 26979396 PMCID: PMC4987166 DOI: 10.1158/1078-0432.ccr-15-2624] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Accepted: 02/18/2016] [Indexed: 12/22/2022]
Abstract
PURPOSE The goal of this study was to identify second-generation mithramycin analogues that better target the EWS-FLI1 transcription factor for Ewing sarcoma. We previously established mithramycin as an EWS-FLI1 inhibitor, but the compound's toxicity prevented its use at effective concentrations in patients. EXPERIMENTAL DESIGN We screened a panel of mithralogs to establish their ability to inhibit EWS-FLI1 in Ewing sarcoma. We compared the IC50 with the MTD established in mice to determine the relationship between efficacy and toxicity. We confirmed the suppression of EWS-FLI1 at the promoter, mRNA, gene signature, and protein levels. We established an improved therapeutic window by using time-lapse microscopy to model the effects on cellular proliferation in Ewing sarcoma cells relative to HepG2 control cells. Finally, we established an improved therapeutic window using a xenograft model of Ewing sarcoma. RESULTS EC-8105 was found to be the most potent analogue and was able to suppress EWS-FLI1 activity at concentrations nontoxic to other cell types. EC-8042 was substantially less toxic than mithramycin in multiple species but maintained suppression of EWS-FLI1 at similar concentrations. Both compounds markedly suppressed Ewing sarcoma xenograft growth and inhibited EWS-FLI1 in vivo CONCLUSIONS These results provide a basis for the continued development of EC-8042 and EC-8105 as EWS-FLI1 inhibitors for the clinic. Clin Cancer Res; 22(16); 4105-18. ©2016 AACR.
Collapse
MESH Headings
- Animals
- Antibiotics, Antineoplastic/pharmacology
- Cell Line, Tumor
- Disease Models, Animal
- Gene Expression Profiling
- Gene Expression Regulation, Neoplastic/drug effects
- Humans
- Mice
- Molecular Targeted Therapy
- Oncogene Proteins, Fusion/antagonists & inhibitors
- Oncogene Proteins, Fusion/metabolism
- Plicamycin/pharmacology
- Promoter Regions, Genetic
- Proto-Oncogene Protein c-fli-1/antagonists & inhibitors
- Proto-Oncogene Protein c-fli-1/metabolism
- RNA-Binding Protein EWS/antagonists & inhibitors
- RNA-Binding Protein EWS/metabolism
- Sarcoma, Ewing/drug therapy
- Sarcoma, Ewing/genetics
- Sarcoma, Ewing/metabolism
- Sarcoma, Ewing/mortality
- Transcription Factors
- Xenograft Model Antitumor Assays
Collapse
Affiliation(s)
- Christy L Osgood
- Division of Pediatric Hematology/Oncology, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Nichole Maloney
- Division of Pediatric Hematology/Oncology, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Christopher G Kidd
- Division of Pediatric Hematology/Oncology, Vanderbilt University School of Medicine, Nashville, Tennessee
| | | | - Laura Segars
- Division of Pediatric Hematology/Oncology, Vanderbilt University School of Medicine, Nashville, Tennessee. Pediatric Oncology Branch, National Cancer Institute, Bethesda, Maryland
| | - Meti Gebregiorgis
- Pediatric Oncology Branch, National Cancer Institute, Bethesda, Maryland
| | - Girma M Woldemichael
- Basic Science Program, Leidos Biomedical Research Laboratory, Inc., Molecular Targets Laboratory, Frederick National Laboratory for Cancer Research, Frederick, Maryland
| | - Min He
- Developmental Therapeutics Program, Division of Cancer Treatment and Diagnosis, National Cancer Institute, National Institutes of Health, Bethesda, Maryland
| | - Savita Sankar
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, Missouri
| | - Stephen L Lessnick
- Center for Childhood Cancer and Blood Disorders, Nationwide Children's Hospital, Division of Pediatric Hematology/Oncology/BMT, The Ohio State University, Columbus, Ohio
| | - Min Kang
- Texas Tech University Health Science Center, School of Medicine, Lubbock, Texas
| | - Malcolm Smith
- Pediatric Oncology Branch, National Cancer Institute, Bethesda, Maryland. Developmental Therapeutics Program, Division of Cancer Treatment and Diagnosis, National Cancer Institute, National Institutes of Health, Bethesda, Maryland
| | - Lisa Turner
- Van Andel Research Institute, Grand Rapids, Michigan
| | | | - Mary E Winn
- Van Andel Research Institute, Grand Rapids, Michigan
| | | | | | - Lee J Helman
- Pediatric Oncology Branch, National Cancer Institute, Bethesda, Maryland
| | | | - Patrick J Grohar
- Division of Pediatric Hematology/Oncology, Vanderbilt University School of Medicine, Nashville, Tennessee. Van Andel Research Institute, Grand Rapids, Michigan. Helen De Vos Children's Hospital, Grand Rapids, Michigan. Department of Pediatrics, Michigan State University School of Medicine, East Lansing, Michigan.
| |
Collapse
|
22
|
EWS-FLI1-mediated suppression of the RAS-antagonist Sprouty 1 (SPRY1) confers aggressiveness to Ewing sarcoma. Oncogene 2016; 36:766-776. [PMID: 27375017 DOI: 10.1038/onc.2016.244] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Revised: 05/05/2016] [Accepted: 05/30/2016] [Indexed: 02/07/2023]
Abstract
Ewing sarcoma is characterized by chromosomal translocations fusing the EWS gene with various members of the ETS family of transcription factors, most commonly FLI1. EWS-FLI1 is an aberrant transcription factor driving Ewing sarcoma tumorigenesis by either transcriptionally inducing or repressing specific target genes. Herein, we showed that Sprouty 1 (SPRY1), which is a physiological negative feedback inhibitor downstream of fibroblast growth factor (FGF) receptors (FGFRs) and other RAS-activating receptors, is an EWS-FLI1 repressed gene. EWS-FLI1 knockdown specifically increased the expression of SPRY1, while other Sprouty family members remained unaffected. Analysis of SPRY1 expression in a panel of Ewing sarcoma cells showed that SPRY1 was not expressed in Ewing sarcoma cell lines, suggesting that it could act as a tumor suppressor gene in these cells. In agreement, induction of SPRY1 in three different Ewing sarcoma cell lines functionally impaired proliferation, clonogenic growth and migration. In addition, SPRY1 expression inhibited extracellular signal-related kinase/mitogen-activated protein kinase (MAPK) signaling induced by serum and basic FGF (bFGF). Moreover, treatment of Ewing sarcoma cells with the potent FGFR inhibitor PD-173074 reduced bFGF-induced proliferation, colony formation and in vivo tumor growth in a dose-dependent manner, thus mimicking SPRY1 activity in Ewing sarcoma cells. Although the expression of SPRY1 was low when compared with other tumors, SPRY1 was variably expressed in primary Ewing sarcoma tumors and higher expression levels were significantly associated with improved outcome in a large patient cohort. Taken together, our data indicate that EWS-FLI1-mediated repression of SPRY1 leads to unrestrained bFGF-induced cell proliferation, suggesting that targeting the FGFR/MAPK pathway can constitute a promising therapeutic approach for this devastating disease.
Collapse
|
23
|
Cidre-Aranaz F, Alonso J. EWS/FLI1 Target Genes and Therapeutic Opportunities in Ewing Sarcoma. Front Oncol 2015; 5:162. [PMID: 26258070 PMCID: PMC4507460 DOI: 10.3389/fonc.2015.00162] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2015] [Accepted: 07/06/2015] [Indexed: 12/31/2022] Open
Abstract
Ewing sarcoma is an aggressive bone malignancy that affect children and young adults. Ewing sarcoma is the second most common primary bone malignancy in pediatric patients. Although significant progress has been made in the treatment of Ewing sarcoma since it was first described in the 1920s, in the last decade survival rates have remained unacceptably invariable, thus pointing to the need for new approaches centered in the molecular basis of the disease. Ewing sarcoma driving mutation, EWS–FLI1, which results from a chromosomal translocation, encodes an aberrant transcription factor. Since its first characterization in 1990s, many molecular targets have been described to be regulated by this chimeric transcription factor. Their contribution to orchestrate Ewing sarcoma phenotype has been reported over the last decades. In this work, we will focus on the description of a selection of EWS/FLI1 targets, their functional role, and their potential clinical relevance. We will also discuss their role in other types of cancer as well as the need for further studies to be performed in order to achieve a broader understanding of their particular contribution to Ewing sarcoma development.
Collapse
Affiliation(s)
- Florencia Cidre-Aranaz
- Unidad de Tumores Sólidos Infantiles, Área de Genética Humana, Instituto de Investigación de Enfermedades Raras, Instituto de Salud Carlos III , Madrid , Spain
| | - Javier Alonso
- Unidad de Tumores Sólidos Infantiles, Área de Genética Humana, Instituto de Investigación de Enfermedades Raras, Instituto de Salud Carlos III , Madrid , Spain
| |
Collapse
|
24
|
Virgone C, Lalli E, Bisogno G, Lazzari E, Roma J, Zin A, Poli E, Cecchetto G, Dall’Igna P, Alaggio R. DAX-1 Expression in Pediatric Rhabdomyosarcomas: Another Immunohistochemical Marker Useful in the Diagnosis of Translocation Positive Alveolar Rhabdomyosarcoma. PLoS One 2015; 10:e0133019. [PMID: 26168243 PMCID: PMC4500404 DOI: 10.1371/journal.pone.0133019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Accepted: 06/23/2015] [Indexed: 12/02/2022] Open
Abstract
Objectives The aim of this study was to investigate the expression of DAX-1 in a series of pediatric rhabdomyosarcomas (RMS) with known translocation and compare it to Ap2β, known to be selectively expressed in ARMS. Design We revised a series of 71 alveolar rhabdomyosarcomas (ARMS), enrolled in the Italian Protocols RMS 79 and 96, and 23 embryonal rhabdomyosarcomas (ERMS) as controls. Before investigating Ap2β and DAX-1, ARMS were reviewed and reclassified as 48 ARMS and 23 non-ARMS. Results Translocation positive ARMS showed a characteristic Ap2β/DAX-1+ staining pattern in 78% of cases, while 76% of classic ERMS were negative for both. Ap2β alone was positive in 3.9% of RMS lacking translocation, whereas DAX-1 alone was positive in 25.4%. Conversely, 9% and 6% of translocation positive ARMS were positive only for DAX-1 or Ap2β, respectively. The 23 non-ARMS shared the same phenotype as ERMS but had a higher frequency of DAX-1 expression. Conclusions DAX-1 is less specific than Ap2β, however it is a sensitive marker for translocation positive ARMS and can be helpful in their diagnosis if used in combination with Ap2β.
Collapse
Affiliation(s)
- Calogero Virgone
- Pediatric Surgery, Department of Women’s and Children’s Health, University-Hospital of Padua, Padua, Italy
- * E-mail:
| | - Enzo Lalli
- Institut de Pharmacologie Moléculaire et Cellulaire, Unité Mixte de Recherche 7275, CNRS, Valbonne, France
- Université de Nice–Sophia Antipolis, Valbonne, France
| | - Gianni Bisogno
- Hematology Oncology, Department of Women’s and Children’s Health, University-Hospital of Padua, Padua, Italy
| | - Elena Lazzari
- Pathology Unit, San Bortolo Hospital, Vicenza, Italy
| | - Josep Roma
- Laboratory of Translational Research in Pediatric Cancer, Vall d’Hebron Research Institute, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Angelica Zin
- Istituto della Ricerca Pediatrica "Città della Speranza", Laboratorio di Biologia dei Tumori Solidi, Padova, Italy
| | - Elena Poli
- Istituto della Ricerca Pediatrica "Città della Speranza", Laboratorio di Biologia dei Tumori Solidi, Padova, Italy
| | - Giovanni Cecchetto
- Pediatric Surgery, Department of Women’s and Children’s Health, University-Hospital of Padua, Padua, Italy
| | - Patrizia Dall’Igna
- Pediatric Surgery, Department of Women’s and Children’s Health, University-Hospital of Padua, Padua, Italy
| | - Rita Alaggio
- Pathology Unit, Department of Medical and Diagnostic Sciences and Special Therapies, University of Padua, Padua, Italy
| |
Collapse
|
25
|
Mariño-Enríquez A, Fletcher CD. Round cell sarcomas – Biologically important refinements in subclassification. Int J Biochem Cell Biol 2014; 53:493-504. [DOI: 10.1016/j.biocel.2014.04.022] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2014] [Revised: 04/23/2014] [Accepted: 04/26/2014] [Indexed: 12/19/2022]
|
26
|
Role of Orphan Nuclear Receptor DAX-1/NR0B1 in Development, Physiology, and Disease. ACTA ACUST UNITED AC 2014. [DOI: 10.1155/2014/582749] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
DAX-1/NR0B1 is an unusual orphan receptor that has a pivotal role in the development and function of steroidogenic tissues and of the reproductive axis. Recent studies have also indicated that this transcription factor has an important function in stem cell biology and in several types of cancer. Here I critically review the most important findings on the role of DAX-1 in development, physiology, and disease of endocrine tissues since the cloning of its gene twenty years ago.
Collapse
|
27
|
Safe S, Jin UH, Hedrick E, Reeder A, Lee SO. Minireview: role of orphan nuclear receptors in cancer and potential as drug targets. Mol Endocrinol 2013; 28:157-72. [PMID: 24295738 DOI: 10.1210/me.2013-1291] [Citation(s) in RCA: 115] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
The nuclear orphan receptors for which endogenous ligands have not been identified include nuclear receptor (NR)0B1 (adrenal hypoplasia congenita critical region on chromosome X gene), NR0B2 (small heterodimer partner), NR1D1/2 (Rev-Erbα/β), NR2C1 (testicular receptor 2), NR2C2 (testicular receptor 4), NR2E1 (tailless), NR2E3 (photoreceptor-specific NR [PNR]), NR2F1 chicken ovalbumin upstream promoter transcription factor 1 (COUP-TFI), NR2F2 (COUP-TFII), NR2F6 (v-erbA-related protein), NR4A1 (Nur77), NR4A2 (Nurr1), NR4A3 (Nor1), and NR6A1 (GCNF). These receptors play essential roles in development, cellular homeostasis, and disease including cancer where over- or underexpression of some receptors has prognostic significance for patient survival. Results of receptor knockdown or overexpression in vivo and in cancer cell lines demonstrate that orphan receptors exhibit tumor-specific pro-oncogenic or tumor suppressor-like activity. For example, COUP-TFII expression is both a positive (ovarian) and negative (prostate and breast) prognostic factor for cancer patients; in contrast, the prognostic activity of adrenal hypoplasia congenita critical region on chromosome X gene for the same tumors is the inverse of COUP-TFII. Functional studies show that Nur77 is tumor suppressor like in acute leukemia, whereas silencing Nur77 in pancreatic, colon, lung, lymphoma, melanoma, cervical, ovarian, gastric, and some breast cancer cell lines induces one or more of several responses including growth inhibition and decreased survival, migration, and invasion. Although endogenous ligands for the orphan receptors have not been identified, there is increasing evidence that different structural classes of compounds activate, inactivate, and directly bind several orphan receptors. Thus, the screening and development of selective orphan receptor modulators will have important clinical applications as novel mechanism-based agents for treating cancer patients overexpressing one or more orphan receptors and also for combined drug therapies.
Collapse
Affiliation(s)
- Stephen Safe
- Department of Veterinary Physiology and Pharmacology (S.S., E.H., A.R.), Texas A&M University, College Station, Texas 77808; and Institute of Biosciences and Technology (S.S., U.-H.J., S.-O.L.), Texas A&M Health Science Center, Houston, Texas 77030
| | | | | | | | | |
Collapse
|
28
|
Agra N, Cidre F, García-García L, de la Parra J, Alonso J. Lysyl oxidase is downregulated by the EWS/FLI1 oncoprotein and its propeptide domain displays tumor supressor activities in Ewing sarcoma cells. PLoS One 2013; 8:e66281. [PMID: 23750284 PMCID: PMC3672102 DOI: 10.1371/journal.pone.0066281] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2012] [Accepted: 05/09/2013] [Indexed: 12/15/2022] Open
Abstract
Ewing sarcoma is the second most common bone malignancy in children and young adults. It is driven by oncogenic fusion proteins (i.e. EWS/FLI1) acting as aberrant transcription factors that upregulate and downregulate target genes, leading to cellular transformation. Thus, identificating these target genes and understanding their contribution to Ewing sarcoma tumorigenesis are key for the development of new therapeutic strategies. In this study we show that lysyl oxidase (LOX), an enzyme involved in maintaining structural integrity of the extracellular matrix, is downregulated by the EWS/FLI1 oncoprotein and in consequence it is not expressed in Ewing sarcoma cells and primary tumors. Using a doxycycline inducible system to restore LOX expression in an Ewing sarcoma derived cell line, we showed that LOX displays tumor suppressor activities. Interestingly, we showed that the tumor suppressor activity resides in the propeptide domain of LOX (LOX-PP), an N-terminal domain produced by proteolytic cleavage during the physiological processing of LOX. Expression of LOX-PP reduced cell proliferation, cell migration, anchorage-independent growth in soft agar and formation of tumors in immunodeficient mice. By contrast, the C-terminal domain of LOX, which contains the enzymatic activity, had the opposite effects, corroborating that the tumor suppressor activity of LOX is mediated exclusively by its propeptide domain. Finally, we showed that LOX-PP inhibits ERK/MAPK signalling pathway, and that many pathways involved in cell cycle progression were significantly deregulated by LOX-PP, providing a mechanistic explanation to the cell proliferation inhibition observed upon LOX-PP expression. In summary, our observations indicate that deregulation of the LOX gene participates in Ewing sarcoma development and identify LOX-PP as a new therapeutic target for one of the most aggressive paediatric malignancies. These findings suggest that therapeutic strategies based on the administration of LOX propeptide or functional analogues could be useful for the treatment of this devastating paediatric cancer.
Collapse
Affiliation(s)
- Noelia Agra
- Unidad de Tumores Sólidos Infantiles, Área de Genética Humana, Instituto de Investigación de Enfermedades Raras, Instituto de Salud Carlos III, Majadahonda, Madrid, Spain
| | - Florencia Cidre
- Unidad de Tumores Sólidos Infantiles, Área de Genética Humana, Instituto de Investigación de Enfermedades Raras, Instituto de Salud Carlos III, Majadahonda, Madrid, Spain
| | - Laura García-García
- Unidad de Tumores Sólidos Infantiles, Área de Genética Humana, Instituto de Investigación de Enfermedades Raras, Instituto de Salud Carlos III, Majadahonda, Madrid, Spain
| | - Juan de la Parra
- Unidad de Tumores Sólidos Infantiles, Área de Genética Humana, Instituto de Investigación de Enfermedades Raras, Instituto de Salud Carlos III, Majadahonda, Madrid, Spain
| | - Javier Alonso
- Unidad de Tumores Sólidos Infantiles, Área de Genética Humana, Instituto de Investigación de Enfermedades Raras, Instituto de Salud Carlos III, Majadahonda, Madrid, Spain
| |
Collapse
|
29
|
Abstract
The orphan nuclear receptors (ONRs) are a vital class of transcriptional regulators belonging to the larger nuclear receptors (NRs) superfamily in higher eukaryotes. As a result of non-identification of endogenous physiological ligands for this class of NRs, they are designated as "orphans". The ONRs on receiving appropriate signals translate into specific gene regulation. Elaborate studies on the ONRs in the past two decades have revealed crucial biological functions controlled by them relating to general metabolism, immunity, organogenesis, angiogenesis, growth and development, and numerous other tissue physiologies. Over the years, many of the ONRs have been studied for their participatory role in human health and disease. Results obtained are encouraging and interesting and shows a number of ONRs does modulate several patho-physiological conditions such as cancer and diabetes. This review discusses the current status about the interplay between select ONRs in cancer and diabetes.
Collapse
Affiliation(s)
- Harmit S Ranhotra
- Orphan Nuclear Receptors Laboratory, Department of Biochemistry, St. Edmund's College, Shillong, India.
| |
Collapse
|
30
|
Camões MJ, Paulo P, Ribeiro FR, Barros-Silva JD, Almeida M, Costa VL, Cerveira N, Skotheim RI, Lothe RA, Henrique R, Jerónimo C, Teixeira MR. Potential downstream target genes of aberrant ETS transcription factors are differentially affected in Ewing's sarcoma and prostate carcinoma. PLoS One 2012. [PMID: 23185447 PMCID: PMC3501462 DOI: 10.1371/journal.pone.0049819] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
FLI1 and ERG, the major ETS transcription factors involved in rearrangements in the Ewing's sarcoma family of tumors (ESFT) and in prostate carcinomas (PCa), respectively, belong to the same subfamily, having 98% sequence identity in the DNA binding domain. We therefore decided to investigate whether the aberrant transcription factors in both malignancies have some common downstream targets. We crossed a publicly available list of all putative EWSR1-FLI1 target genes in ESFT with our microarray expression data on 24 PCa and 6 non-malignant prostate tissues (NPT) and choose four genes among the top-most differentially expressed between PCa with (PCa ERG+) and without (PCa ETS-) ETS fusion genes (HIST1H4L, KCNN2, ECRG4 and LDOC1), as well as four well-validated direct targets of the EWSR1-FLI1 chimeric protein in ESFT (NR0B1, CAV1, IGFBP3 and TGFBR2). Using quantitative expression analysis in 16 ESFT and seven alveolar rhabdomyosarcomas (ARMS), we were able to validate the four genes previously described as direct targets of the EWSR1-FLI1 oncoprotein, showing overexpression of CAV1 and NR0B1 and underexpression of IGFBP3 and TGFBR2 in ESFT as compared to ARMS. Although none of these four genes showed significant expression differences between PCa ERG+ and PCa ETS-, CAV1, IGFBP3 and TGFBR2 were less expressed in PCa in an independent series of 56 PCa and 15 NPT, as also observed for ECRG4 and LDOC1, suggesting a role in prostate carcinogenesis in general. On the other hand, we demonstrate for the first time that both HIST1H4L and KCNN2 are significantly overexpressed in PCa ERG+ and that ERG binds to the promoter of these genes. Conversely, KCNN2 was found underexpressed in ESFT relative to ARMS, suggesting that the EWSR1-ETS oncoprotein may have the opposite effect of ERG rearrangements in PCa. We conclude that aberrant ETS transcription factors modulate target genes differently in ESFT and PCa.
Collapse
MESH Headings
- Caveolin 1/genetics
- Caveolin 1/metabolism
- Cell Line, Tumor
- DAX-1 Orphan Nuclear Receptor/genetics
- DAX-1 Orphan Nuclear Receptor/metabolism
- DNA-Binding Proteins
- Gene Expression Regulation, Neoplastic
- Humans
- Insulin-Like Growth Factor Binding Protein 3/genetics
- Insulin-Like Growth Factor Binding Protein 3/metabolism
- Male
- Microarray Analysis
- Oncogene Proteins, Fusion/genetics
- Oncogene Proteins, Fusion/metabolism
- Prostatic Neoplasms/genetics
- Prostatic Neoplasms/metabolism
- Prostatic Neoplasms/pathology
- Protein Serine-Threonine Kinases/genetics
- Protein Serine-Threonine Kinases/metabolism
- Proto-Oncogene Protein c-fli-1/genetics
- Proto-Oncogene Protein c-fli-1/metabolism
- Proto-Oncogene Proteins c-ets/genetics
- Proto-Oncogene Proteins c-ets/metabolism
- Receptor, Transforming Growth Factor-beta Type II
- Receptors, Transforming Growth Factor beta/genetics
- Receptors, Transforming Growth Factor beta/metabolism
- Sarcoma, Ewing/genetics
- Sarcoma, Ewing/metabolism
- Sarcoma, Ewing/pathology
- Trans-Activators/genetics
- Trans-Activators/metabolism
- Transcriptional Regulator ERG
Collapse
Affiliation(s)
- Maria J. Camões
- Department of Genetics, Portuguese Oncology Institute-Porto, Porto, Portugal
- Cancer Genetics Group, Research Centre of the Portuguese Oncology Institute-Porto, Porto, Portugal
| | - Paula Paulo
- Department of Genetics, Portuguese Oncology Institute-Porto, Porto, Portugal
- Cancer Genetics Group, Research Centre of the Portuguese Oncology Institute-Porto, Porto, Portugal
| | - Franclim R. Ribeiro
- Department of Genetics, Portuguese Oncology Institute-Porto, Porto, Portugal
- Cancer Genetics Group, Research Centre of the Portuguese Oncology Institute-Porto, Porto, Portugal
| | - João D. Barros-Silva
- Department of Genetics, Portuguese Oncology Institute-Porto, Porto, Portugal
- Cancer Genetics Group, Research Centre of the Portuguese Oncology Institute-Porto, Porto, Portugal
| | - Mafalda Almeida
- Department of Genetics, Portuguese Oncology Institute-Porto, Porto, Portugal
- Cancer Epigenetics Group, Research Centre of The Portuguese Oncology Institute, Porto, Portugal
| | - Vera L. Costa
- Department of Genetics, Portuguese Oncology Institute-Porto, Porto, Portugal
- Cancer Epigenetics Group, Research Centre of The Portuguese Oncology Institute, Porto, Portugal
| | - Nuno Cerveira
- Department of Genetics, Portuguese Oncology Institute-Porto, Porto, Portugal
- Cancer Genetics Group, Research Centre of the Portuguese Oncology Institute-Porto, Porto, Portugal
| | - Rolf I. Skotheim
- Department of Cancer Prevention, Institute for Cancer Research, Norwegian Radium Hospital, Oslo University Hospital, Oslo, Norway
- Centre for Cancer Biomedicine, Faculty of Medicine, University of Oslo, Oslo, Norway
| | - Ragnhild A. Lothe
- Department of Cancer Prevention, Institute for Cancer Research, Norwegian Radium Hospital, Oslo University Hospital, Oslo, Norway
- Centre for Cancer Biomedicine, Faculty of Medicine, University of Oslo, Oslo, Norway
| | - Rui Henrique
- Cancer Epigenetics Group, Research Centre of The Portuguese Oncology Institute, Porto, Portugal
- Department of Pathology, Portuguese Oncology Institute-Porto, Porto, Portugal
- Department of Pathology and Molecular Immunology, Institute of Biomedical Sciences Abel Salazar (ICBAS), University of Porto, Porto, Portugal
| | - Carmen Jerónimo
- Department of Genetics, Portuguese Oncology Institute-Porto, Porto, Portugal
- Cancer Epigenetics Group, Research Centre of The Portuguese Oncology Institute, Porto, Portugal
- Department of Pathology and Molecular Immunology, Institute of Biomedical Sciences Abel Salazar (ICBAS), University of Porto, Porto, Portugal
| | - Manuel R. Teixeira
- Department of Genetics, Portuguese Oncology Institute-Porto, Porto, Portugal
- Cancer Genetics Group, Research Centre of the Portuguese Oncology Institute-Porto, Porto, Portugal
- Centre for Cancer Biomedicine, Faculty of Medicine, University of Oslo, Oslo, Norway
- Department of Pathology and Molecular Immunology, Institute of Biomedical Sciences Abel Salazar (ICBAS), University of Porto, Porto, Portugal
- * E-mail:
| |
Collapse
|
31
|
Targeting the EWSR1-FLI1 Oncogene-Induced Protein Kinase PKC-β Abolishes Ewing Sarcoma Growth. Cancer Res 2012; 72:4494-503. [DOI: 10.1158/0008-5472.can-12-0371] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
32
|
Susaki Y, Inoue M, Minami M, Sawabata N, Shintani Y, Nakagiri T, Funaki S, Aozasa K, Okumura M, Morii E. Inhibitory effect of PPARγ on NR0B1 in tumorigenesis of lung adenocarcinoma. Int J Oncol 2012; 41:1278-84. [PMID: 22843091 DOI: 10.3892/ijo.2012.1571] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2012] [Accepted: 05/18/2012] [Indexed: 11/05/2022] Open
Abstract
NR0B1, an orphan nuclear receptor, is expressed in side population cells and its knockdown reduces tumorigenic and anti-apoptotic potential in lung adenocarcinoma. Peroxisome proliferator-activated receptor γ (PPARγ) is another member of the nuclear receptor family which induces apoptosis in lung cancer. The interaction of NR0B1 with PPARγ was examined. The transactivation ability of PPARγ was inhibited by NR0B1 in lung adenocarcinoma, and the N-terminal region of NR0B1 containing LxxLL motifs mediated its inhibition. Co-immunoprecipitation experiments revealed that this N-terminal region of NR0B1 was essential for the physical interaction with PPARγ. Aldehyde dehydrogenase (ALDH) activity and ALDH3A1 expression, which are correlated with tumorigenic potential of lung adenocarcinoma, increased when NR0B1 expression was induced, but its increase was inhibited by PPARγ overexpression. ALDH activity increased by treatment with PPARγ inhibitor, and the increase was further enhanced when the expression of NR0B1 was induced. Furthermore, the high NR0B1 and low PPARγ expression was a negative prognostic factor in Pathological-Stage IA clinical cases. These results indicate the reciprocal relationship between NR0B1 and PPARγ on the malignant grade of lung adenocarcinoma.
Collapse
Affiliation(s)
- Yoshiyuki Susaki
- Department of Pathology, Osaka University Graduate School of Medicine, Suita 565-0871, Japan
| | | | | | | | | | | | | | | | | | | |
Collapse
|
33
|
Monument MJ, Johnson KM, Grossmann AH, Schiffman JD, Randall RL, Lessnick SL. Microsatellites with macro-influence in ewing sarcoma. Genes (Basel) 2012; 3:444-60. [PMID: 24704979 PMCID: PMC3899989 DOI: 10.3390/genes3030444] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2012] [Revised: 07/04/2012] [Accepted: 07/05/2012] [Indexed: 01/02/2023] Open
Abstract
Numerous molecular abnormalities contribute to the genetic derangements involved in tumorigenesis. Chromosomal translocations are a frequent source of these derangements, producing unique fusion proteins with novel oncogenic properties. EWS/ETS fusions in Ewing sarcoma are a prime example of this, resulting in potent chimeric oncoproteins with novel biological properties and a unique transcriptional signature essential for oncogenesis. Recent evidence demonstrates that EWS/FLI, the most common EWS/ETS fusion in Ewing sarcoma, upregulates gene expression using a GGAA microsatellite response element dispersed throughout the human genome. These GGAA microsatellites function as enhancer elements, are sites of epigenetic regulation and are necessary for EWS/FLI DNA binding and upregulation of principal oncogenic targets. An increasing number of GGAA motifs appear to substantially enhance EWS/FLI-mediated gene expression, which has compelling biological implications as these GGAA microsatellites are highly polymorphic within and between ethnically distinct populations. Historically regarded as junk DNA, this emerging evidence clearly demonstrates that microsatellite DNA plays an instrumental role in EWS/FLI-mediated transcriptional regulation and oncogenesis in Ewing sarcoma. This unprecedented role of GGAA microsatellite DNA in Ewing sarcoma provides a unique opportunity to expand our mechanistic understanding of how EWS/ETS fusions influence cancer susceptibility, prognosis and transcriptional regulation.
Collapse
Affiliation(s)
- Michael J Monument
- Center for Children's Cancer Research, Huntsman Cancer Institute, University of Utah, Salt Lake City, UT 84112, USA.
| | - Kirsten M Johnson
- Center for Children's Cancer Research, Huntsman Cancer Institute, University of Utah, Salt Lake City, UT 84112, USA.
| | - Allie H Grossmann
- Department of Pathology and Program in Molecular Medicine, University of Utah, Salt Lake City, UT 84112, USA.
| | - Joshua D Schiffman
- Center for Children's Cancer Research, Huntsman Cancer Institute, University of Utah, Salt Lake City, UT 84112, USA.
| | - R Lor Randall
- Center for Children's Cancer Research, Huntsman Cancer Institute, University of Utah, Salt Lake City, UT 84112, USA.
| | - Stephen L Lessnick
- Center for Children's Cancer Research, Huntsman Cancer Institute, University of Utah, Salt Lake City, UT 84112, USA.
| |
Collapse
|
34
|
Ehrlund A, Treuter E. Ligand-independent actions of the orphan receptors/corepressors DAX-1 and SHP in metabolism, reproduction and disease. J Steroid Biochem Mol Biol 2012; 130:169-79. [PMID: 21550402 DOI: 10.1016/j.jsbmb.2011.04.007] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2010] [Revised: 03/11/2011] [Accepted: 04/21/2011] [Indexed: 12/11/2022]
Abstract
DAX-1 and SHP are two closely related atypical orphan members of the nuclear receptor (NR) family that make up the NR0B subfamily. They combine properties of typical NRs and of NR-associated coregulators: both carry the characteristic NR ligand-binding domain but instead of a NR DNA-binding domain they have unique N-terminal regions that contain LxxLL-related NR-binding motifs often found in coregulators. Recent structural data indicate that DAX-1 lacks a ligand-binding pocket and thus should rely on ligand-independent mechanisms of regulation. This might be true, but remains to be proven, for SHP as well. DAX-1 and SHP have in common that they act as transcriptional corepressors of cholesterol metabolism pathways that are related on a molecular level. However, the expression patterns of the two NRs are largely different, with some notable exceptions, and so are the physiological processes they regulate. DAX-1 is mainly involved in steroidogenesis and reproductive development, while SHP plays major roles in maintaining cholesterol and glucose homeostasis. This review highlights the key similarities and differences between DAX-1 and SHP with regard to structure, function and biology and considers what can be learnt from recent research advances in the field. This article is part of a Special Issue entitled 'Orphan Receptors'.
Collapse
Affiliation(s)
- Anna Ehrlund
- Center for Biosciences, Department of Biosciences and Nutrition, Karolinska Institutet, S-14183 Huddinge/Stockholm, Sweden
| | | |
Collapse
|
35
|
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.
Collapse
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.
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
36
|
France KA, Anderson JL, Park A, Denny CT. Oncogenic fusion protein EWS/FLI1 down-regulates gene expression by both transcriptional and posttranscriptional mechanisms. J Biol Chem 2011; 286:22750-7. [PMID: 21531709 DOI: 10.1074/jbc.m111.225433] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Ewing family tumors are characterized by a translocation between the RNA binding protein EWS and one of five ETS transcription factors, most commonly FLI1. The fusion protein produced by the translocation has been thought to act as an aberrant transcription factor, leading to changes in gene expression and cellular transformation. In this study, we investigated the specific processes EWS/FLI1 utilizes to alter gene expression. Using both heterologous NIH 3T3 and human Ewing Family Tumor cell lines, we have demonstrated by quantitative pre-mRNA analysis that EWS/FLI1 repressed the expression of previously validated direct target genes at the level of transcript synthesis. ChIP experiments showed that EWS/FLI1 decreases the amount of Pol II at the promoter of down-regulated genes in both murine and human model systems. However, in down-regulated target genes, there was a significant disparity between the modulation of cognate mRNA and pre-mRNAs, suggesting that these genes could also be regulated at a posttranscriptional level. Confirming this, we found that EWS/FLI1 decreased the transcript half-life of insulin-like growth factor binding protein 3, a down-regulated direct target gene in human tumor-derived Ewing's sarcoma cell lines. Additionally, we have shown through reexpression experiments that full EWS/FLI1-mediated transcriptional repression requires intact EWS and ETS domains. Together these data demonstrate that EWS/FLI1 can dictate steady-state target gene expression by modulating both transcript synthesis and degradation.
Collapse
Affiliation(s)
- Kelly A France
- Molecular Biology Institute, University of California, Los Angeles, California 90095, USA
| | | | | | | |
Collapse
|
37
|
Dr. Jekyll and Mr. Hyde: The Two Faces of the FUS/EWS/TAF15 Protein Family. Sarcoma 2010; 2011:837474. [PMID: 21197473 PMCID: PMC3005952 DOI: 10.1155/2011/837474] [Citation(s) in RCA: 93] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2010] [Revised: 10/20/2010] [Accepted: 11/01/2010] [Indexed: 12/13/2022] Open
Abstract
FUS, EWS, and TAF15 form the FET family of RNA-binding proteins whose genes are found rearranged with various transcription factor genes predominantly in sarcomas and in rare hematopoietic and epithelial cancers. The resulting fusion gene products have attracted considerable interest as diagnostic and promising therapeutic targets. So far, oncogenic FET fusion proteins have been regarded as strong transcription factors that aberrantly activate or repress target genes of their DNA-binding fusion partners. However, the role of the transactivating domain in the context of the normal FET proteins is poorly defined, and, therefore, our knowledge on how FET aberrations impact on tumor biology is incomplete. Since we believe that a full understanding of aberrant FET protein function can only arise from looking at both sides of the coin, the good and the evil, this paper summarizes evidence for the central function of FET proteins in bridging RNA transcription, processing, transport, and DNA repair.
Collapse
|
38
|
Erkizan HV, Uversky VN, Toretsky JA. Oncogenic partnerships: EWS-FLI1 protein interactions initiate key pathways of Ewing's sarcoma. Clin Cancer Res 2010; 16:4077-83. [PMID: 20547696 DOI: 10.1158/1078-0432.ccr-09-2261] [Citation(s) in RCA: 106] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Targeted therapy for cancer, which is specifically directed toward the cancer without any potential for effects outside of controlling the tumor, is a gold standard for treatment. Ewing's sarcoma contains the potential target EWS-FLI1, as a result of a pathognomonic chromosomal translocation. The EWS-FLI1 fusion protein includes the EWS domain, a potent transcriptional activator alongside the highly conserved FLI1 ets DNA-binding domain. Because of the combination of these domains, the EWS-FLI1 fusion protein acts as an aberrant transcription factor whose expression results in cellular transformation. EWS-FLI1 functions by binding to normal cellular protein partners in transcription and splicing, similar to how a virus would corrupt normal cellular machinery for virion production. Therefore, understanding the protein-protein interactions of EWS-FLI1 and the pathways that are regulated by these partnerships will inform both oncogenesis and therapeutics. This review describes the known protein partners and transcriptional targets of EWS-FLI1, while proposing strategies for exploiting these partnerships with targeted therapy.
Collapse
Affiliation(s)
- Hayriye V Erkizan
- Department of Oncology and Pediatrics, Lombardi Comprehensive Cancer Center, Georgetown University, Washington, DC, USA
| | | | | |
Collapse
|
39
|
Abstract
IMPORTANCE OF THE FIELD DAX-1 (NR0B1) is an unusual orphan nuclear receptor whose function is essential for the development of the human adrenal cortex and onset of puberty. Recent data have implicated this transcription factor also in embryonic stem cell and cancer biology. AREAS COVERED IN THIS REVIEW The role of DAX-1 in the regulation of development and function of the adrenal cortex, reproductive axis, embryonic stem cells and a few types of cancer. WHAT THE READER WILL GAIN Here we review the past and present milestones in DAX-1 research and try to provide hints about the development and fields of application of DAX-1-targeted drugs in the future. TAKE HOME MESSAGE The unusual structure and restricted expression pattern of DAX-1 may offer unique opportunities for drug discovery.
Collapse
Affiliation(s)
- Enzo Lalli
- Institut de Pharmacologie Moléculaire et Cellulaire CNRS UMR 6097, Valbonne, France.
| | | |
Collapse
|
40
|
Navarro D, Agra N, Pestaña A, Alonso J, González-Sancho JM. The EWS/FLI1 oncogenic protein inhibits expression of the Wnt inhibitor DICKKOPF-1 gene and antagonizes beta-catenin/TCF-mediated transcription. Carcinogenesis 2009; 31:394-401. [PMID: 20019092 DOI: 10.1093/carcin/bgp317] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Tumours of the Ewing family, which comprise Ewing's sarcoma and peripheral primitive neuroectodermal tumours, are highly aggressive and mostly affect children and adolescents. They are characterized by chromosomal translocations leading to the generation of fusion proteins between EWS (or very rarely FUS) and members of the E-twenty-six (ETS) family of transcription factors that are capable of transforming cells. EWS/FLI1, the most frequent fusion, is thought to cause transformation through activation or repression of specific target genes. We present evidence demonstrating that the Wnt inhibitor and beta-catenin/T-cell factor (TCF)-responsive gene DICKKOPF-1 (DKK-1) is a transcriptional target of EWS/FLI1, which can inhibit both basal and beta-catenin-induced transactivation of the DKK-1 promoter. Moreover, our data indicate that EWS/FLI1 has a more general effect on beta-catenin/TCF-mediated transcription since it can block transactivation of a consensus beta-catenin/TCF reporter construct. Consistently, Ewing tumour cells expressing different EWS/ETS translocations cannot engage beta-catenin/TCF-dependent transcription, whereas silencing of EWS/FLI1 restores beta-catenin responsiveness in A673 and RD-ES Ewing tumour cells. Accordingly, gene set enrichment analysis shows that beta-catenin/TCF target genes are significantly enriched among genes downregulated by EWS/FLI1 in the Ewing cell line A673. Mechanistically, the inhibitory effect of EWS/FLI1 can be overcome by a constitutively active TCF4 protein (TCF4-VP16). Moreover, EWS/FLI1 binds lymphoid enhancer factor 1, a TCF family member, and interferes with its binding to beta-catenin, which could explain its negative effect on beta-catenin/TCF-mediated transcription. Our results show that EWS/FLI1 inhibits both DKK-1 expression as well as beta-catenin/TCF-dependent transcription, which could contribute to progression of tumours of the Ewing family.
Collapse
Affiliation(s)
- Diego Navarro
- Departamento de Biología del Cáncer, Instituto de Investigaciones Biomédicas Alberto Sols, Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid, Arturo Duperier 4, E-28029, Madrid, Spain
| | | | | | | | | |
Collapse
|
41
|
Vers une thérapeutique ciblée du sarcome d’Ewing par une stratégie antisens. ONCOLOGIE 2009. [DOI: 10.1007/s10269-009-1826-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
|
42
|
Powers J, Zhao Y, Lin S, McCabe ERB. The expression of nr0b1, the earliest gene in zebrafish tooth development, is a marker for human tooth and ameloblastoma formation. Dev Genes Evol 2009; 219:419-25. [PMID: 19826837 PMCID: PMC2773114 DOI: 10.1007/s00427-009-0300-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2009] [Accepted: 08/12/2009] [Indexed: 11/26/2022]
Abstract
Zebrafish teeth develop on pharyngeal jaws in the 5th branchial arch, but early tooth development is remarkably similar to mammals (Borday-Birraux et al., Evol Dev 8:130, 2006). Recently, eve1 has been shown to be associated with the primary tooth (4V1) and early ameloblast development, the enamel organ precursor (Laurenti et al., Dev Dyn 230:727, 2004). dax1 is initially expressed in the 5th branchial arch in zebrafish at approximately 26 h postfertilization (hpf) and colocalizes with eve1 expression at ~48 hpf. Embryos injected with dax1 morpholino show downregulation of eve1 expression. Based on the zebrafish observations, we demonstrated novel DAX1 expression in normal human dental, benign ameloblastoma, and malignant ameloblastoma tissues. The association of NR0B1 and its protein product DAX1 with primary tooth development and ameloblastoma tumorigenesis is an association not previously described.
Collapse
Affiliation(s)
- Jamie Powers
- Department of Pediatrics, David Geffen School of Medicine, UCLA, 10833 Le Conte Ave., MDCC B2-375, Los Angeles, 90095 CA USA
- Mattel Children’s Hospital, UCLA, Los Angeles, 90095 CA USA
| | - Yan Zhao
- Molecular, Cell and Developmental Biology, UCLA, P.O. Box 951606, 4325 Life Science Bldg, Los Angeles, 90095-1606 CA USA
| | - Shuo Lin
- Molecular, Cell and Developmental Biology, UCLA, P.O. Box 951606, 4325 Life Science Bldg, Los Angeles, 90095-1606 CA USA
| | - Edward R. B. McCabe
- Mattel Children’s Hospital, UCLA, Los Angeles, 90095 CA USA
- Department of Human Genetics, David Geffen School of Medicine, UCLA, Los Angeles, CA USA
- Department of Bioengineering, Henry Samueli School of Engineering and Applied Science, UCLA, Los Angeles, CA USA
- Department of Pediatrics, David Geffen School of Medicine, UCLA, P.O. Box 951752, 22-412 MDCC, Los Angeles, 90095-1752 CA USA
| |
Collapse
|
43
|
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.
Collapse
Affiliation(s)
- Adelene Y Tan
- Department of Biological Sciences, Columbia University, New York, NY 10027, USA
| | | |
Collapse
|
44
|
Nagl F, Schönhofer K, Seidler B, Mages J, Allescher HD, Schmid RM, Schneider G, Saur D. Retinoic acid-induced nNOS expression depends on a novel PI3K/Akt/DAX1 pathway in human TGW-nu-I neuroblastoma cells. Am J Physiol Cell Physiol 2009; 297:C1146-56. [PMID: 19726747 DOI: 10.1152/ajpcell.00034.2009] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Neuronal nitric oxide synthase (nNOS)-derived nitric oxide (NO) acts as a neurotransmitter and intracellular signaling molecule in the central and peripheral nervous system. NO regulates multiple processes like neuronal development, plasticity, and differentiation and is a mediator of neurotoxicity. The nNOS gene is highly complex with 12 alternative first exons, exon 1a-1l, transcribed from distinct promoters, leading to nNOS variants with different 5'-untranslated regions. Transcriptional control of the nNOS gene is not understood in detail. To investigate regulation of nNOS gene expression by retinoic acid (RA), we used the human neuroblastoma cell line TGW-nu-I as a model system. We show that RA induces nNOS transcription in a protein synthesis-dependent fashion. We identify the phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathway and the atypical orphan nuclear receptor DAX1 (NR0B1) as critical mediators involved in RA-induced nNOS gene transcription. RA treatment increases DAX1 expression via PI3K/Akt signaling. Upregulation of DAX1 expression in turn induces nNOS transcription in response to RA. These results identify nNOS as a target gene of a novel RA/PI3K/Akt/DAX1-dependent pathway in human neuroblastoma cells and stress the functional importance of the transcriptional regulator DAX1 for nNOS gene expression in response to RA treatment.
Collapse
Affiliation(s)
- Florian Nagl
- II. Medizinische Klinik, Technische Universität München, 81675 Munich, Germany
| | | | | | | | | | | | | | | |
Collapse
|
45
|
Oda T, Tian T, Inoue M, Ikeda JI, Qiu Y, Okumura M, Aozasa K, Morii E. Tumorigenic role of orphan nuclear receptor NR0B1 in lung adenocarcinoma. THE AMERICAN JOURNAL OF PATHOLOGY 2009; 175:1235-45. [PMID: 19644015 DOI: 10.2353/ajpath.2009.090010] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Cancer stem cells are a limited population of tumor cells that are thought to reconstitute whole tumors. The Hoechst dye exclusion assay revealed that tumors are composed of both a main population and a side population of cells, which are rich in cancer stem cells. NR0B1 is an orphan nuclear receptor that is expressed to a greater extent in the side population, as compared with the main population, of a lung adenocarcinoma cell line. In this study, we investigated the role of NR0B1 in lung adenocarcinoma cells. Reduction of NR0B1 expression levels in lung adenocarcinoma cell lines resulted in vulnerability to anti-cancer drugs and decreased abilities for invasion, in vitro colony formation, and tumorigenicity in non-obese diabetic/severe compromised immunodeficient mice. When 193 cases of lung adenocarcinoma were immunohistochemically examined, higher levels of NR0B1 expression correlated with higher rates of lymph node metastasis and recurrence. Multivariate analysis revealed high NR0B1 expression levels, stage of the disease, and size of tumor to be independent unfavorable prognostic factors for overall and disease-free survival rates. In clinical samples, NR0B1 expression levels inversely correlated to the proportion of methylated CpG sequences around the transcription initiation site of the NR0B1 gene, suggesting the epigenetic control of NR0B1 transcription in lung adenocarcinoma. In conclusion, NR0B1 might play a role in the malignant potential of lung adenocarcinoma.
Collapse
Affiliation(s)
- Tomofumi Oda
- Department of Pathology, Graduate School of Medicine, Osaka University, Yamada-oka 2-2, Suita, Japan
| | | | | | | | | | | | | | | |
Collapse
|
46
|
Khalfallah O, Rouleau M, Barbry P, Bardoni B, Lalli E. Dax-1 Knockdown in Mouse Embryonic Stem Cells Induces Loss of Pluripotency and Multilineage Differentiation. Stem Cells 2009; 27:1529-37. [DOI: 10.1002/stem.78] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
47
|
Else T, Trovato A, Kim AC, Wu Y, Ferguson DO, Kuick RD, Lucas PC, Hammer GD. Genetic p53 deficiency partially rescues the adrenocortical dysplasia phenotype at the expense of increased tumorigenesis. Cancer Cell 2009; 15:465-76. [PMID: 19477426 PMCID: PMC2703790 DOI: 10.1016/j.ccr.2009.04.011] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2008] [Revised: 03/01/2009] [Accepted: 04/27/2009] [Indexed: 12/23/2022]
Abstract
Telomere dysfunction and shortening induce chromosomal instability and tumorigenesis. In this study, we analyze the adrenocortical dysplasia (acd) mouse, harboring a mutation in Tpp1/Acd. Additional loss of p53 dramatically rescues the acd phenotype in an organ-specific manner, including skin hyperpigmentation and adrenal morphology, but not germ cell atrophy. Survival to weaning age is significantly increased in Acd(acd/acd) p53(-/-) mice. On the contrary, p53(-/-) and p53(+/-) mice with the Acd(acd/acd) genotype show a decreased tumor-free survival, compared with Acd(+/+) mice. Tumors from Acd(acd/acd) p53(+/-) mice show a striking switch from the classic spectrum of p53(-/-) mice toward carcinomas. The acd mouse model provides further support for an in vivo role of telomere deprotection in tumorigenesis.
Collapse
Affiliation(s)
- Tobias Else
- Department of Internal Medicine, University of Michigan Health System, Ann Arbor, MI 48109-2200, USA
| | | | | | | | | | | | | | | |
Collapse
|
48
|
Herrero-Martín D, Osuna D, Ordóñez JL, Sevillano V, Martins AS, Mackintosh C, Campos M, Madoz-Gúrpide J, Otero-Motta AP, Caballero G, Amaral AT, Wai DH, Braun Y, Eisenacher M, Schaefer KL, Poremba C, de Alava E. Stable interference of EWS-FLI1 in an Ewing sarcoma cell line impairs IGF-1/IGF-1R signalling and reveals TOPK as a new target. Br J Cancer 2009; 101:80-90. [PMID: 19491900 PMCID: PMC2694277 DOI: 10.1038/sj.bjc.6605104] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND Ewing sarcoma is a paradigm of solid tumour -bearing chromosomal translocations resulting in fusion proteins that act as deregulated transcription factors. Ewing sarcoma translocations fuse the EWS gene with an ETS transcription factor, mainly FLI1. Most of the EWS-FLI1 target genes still remain unknown and many have been identified in heterologous model systems. METHODS We have developed a stable RNA interference model knocking down EWS-FLI1 in the Ewing sarcoma cell line TC71. Gene expression analyses were performed to study the effect of RNA interference on the genetic signature of EWS-FLI1 and to identify genes that could contribute to tumourigenesis. RESULTS EWS-FLI1 inhibition induced apoptosis, reduced cell migratory and tumourigenic capacities, and caused reduction in tumour growth. IGF-1 was downregulated and the IGF-1/IGF-1R signalling pathway was impaired. PBK/TOPK (T-LAK cell-originated protein kinase) expression was decreased because of EWS-FLI1 inhibition. We showed that TOPK is a new target gene of EWS-FLI1. TOPK inhibition prompted a decrease in the proliferation rate and a dramatic change in the cell's ability to grow in coalescence. CONCLUSION This is the first report of TOPK activity in Ewing sarcoma and suggests a significant role of this MAPKK-like protein kinase in the Ewing sarcoma biology.
Collapse
Affiliation(s)
- D Herrero-Martín
- Molecular Pathology Program, Centro de Investigación del Cáncer-IBMCC (USAL-CSIC), Campus Unamuno s/n, Salamanca, Spain.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
49
|
Kauer M, Ban J, Kofler R, Walker B, Davis S, Meltzer P, Kovar H. A molecular function map of Ewing's sarcoma. PLoS One 2009; 4:e5415. [PMID: 19404404 PMCID: PMC2671847 DOI: 10.1371/journal.pone.0005415] [Citation(s) in RCA: 140] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2009] [Accepted: 03/27/2009] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND EWS-FLI1 is a chimeric ETS transcription factor that is, due to a chromosomal rearrangement, specifically expressed in Ewing's sarcoma family tumors (ESFT) and is thought to initiate the development of the disease. Previous genomic profiling experiments have identified EWS-FLI1-regulated genes and genes that discriminate ESFT from other sarcomas, but so far a comprehensive analysis of EWS-FLI1-dependent molecular functions characterizing this aggressive cancer is lacking. METHODOLOGY/PRINCIPAL FINDINGS In this study, a molecular function map of ESFT was constructed based on an integrative analysis of gene expression profiling experiments following EWS-FLI1 knockdown in a panel of five ESFT cell lines, and on gene expression data from the same platform of 59 primary ESFT. Out of 80 normal tissues tested, mesenchymal progenitor cells (MPC) were found to fit the hypothesis that EWS-FLI1 is the driving transcriptional force in ESFT best and were therefore used as the reference tissue for the construction of the molecular function map. The interrelations of molecular pathways were visualized by measuring the similarity among annotated gene functions by gene sharing. The molecular function map highlighted distinct clusters of activities for EWS-FLI1 regulated genes in ESFT and revealed a striking difference between EWS-FLI1 up- and down-regulated genes: EWS-FLI1 induced genes mainly belong to cell cycle regulation, proliferation, and response to DNA damage, while repressed genes were associated with differentiation and cell communication. CONCLUSIONS/SIGNIFICANCE This study revealed that EWS-FLI1 combines by distinct molecular mechanisms two important functions of cellular transformation in one protein, growth promotion and differentiation blockage. By taking MPC as a reference tissue, a significant EWS-FLI1 signature was discovered in ESFT that only partially overlapped with previously published EWS-FLI1-dependent gene expression patterns, identifying a series of novel targets for the chimeric protein in ESFT. Our results may guide target selection for future ESFT specific therapies.
Collapse
Affiliation(s)
- Maximilian Kauer
- Children's Cancer Research Institute, St. Anna Kinderkrebsforschung, Vienna, Austria
| | - Jozef Ban
- Children's Cancer Research Institute, St. Anna Kinderkrebsforschung, Vienna, Austria
| | - Reinhard Kofler
- Biocenter, Division of Molecular Pathophysiology, Medical University Innsbruck, Innsbruck, Austria
| | - Bob Walker
- Genetics Branch, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Sean Davis
- Genetics Branch, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Paul Meltzer
- Genetics Branch, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Heinrich Kovar
- Children's Cancer Research Institute, St. Anna Kinderkrebsforschung, Vienna, Austria
- * E-mail:
| |
Collapse
|
50
|
The oncogenic EWS-FLI1 protein binds in vivo GGAA microsatellite sequences with potential transcriptional activation function. PLoS One 2009; 4:e4932. [PMID: 19305498 PMCID: PMC2654724 DOI: 10.1371/journal.pone.0004932] [Citation(s) in RCA: 132] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2009] [Accepted: 02/21/2009] [Indexed: 12/21/2022] Open
Abstract
The fusion between EWS and ETS family members is a key oncogenic event in Ewing tumors and important EWS-FLI1 target genes have been identified. However, until now, the search for EWS-FLI1 targets has been limited to promoter regions and no genome-wide comprehensive analysis of in vivo EWS-FLI1 binding sites has been undertaken. Using a ChIP-Seq approach to investigate EWS-FLI1-bound DNA sequences in two Ewing cell lines, we show that this chimeric transcription factor preferentially binds two types of sequences including consensus ETS motifs and microsatellite sequences. Most bound sites are found outside promoter regions. Microsatellites containing more than 9 GGAA repeats are very significantly enriched in EWS-FLI1 immunoprecipitates. Moreover, in reporter gene experiments, the transcription activation is highly dependent upon the number of repeats that are included in the construct. Importantly, in vivo EWS-FLI1-bound microsatellites are significantly associated with EWS-FLI1-driven gene activation. Put together, these results point out the likely contribution of microsatellite elements to long-distance transcription regulation and to oncogenesis.
Collapse
|