1
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Exploration of Alternative Splicing (AS) Events in MDV-Infected Chicken Spleens. Genes (Basel) 2021; 12:genes12121857. [PMID: 34946806 PMCID: PMC8701255 DOI: 10.3390/genes12121857] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Revised: 11/18/2021] [Accepted: 11/19/2021] [Indexed: 11/16/2022] Open
Abstract
Marek’s disease (MD) was an immunosuppression disease induced by Marek’s disease virus (MDV). MD caused huge economic loss to the global poultry industry, but it also provided an ideal model for studying diseases induced by the oncogenic virus. Alternative splicing (AS) simultaneously produced different isoform transcripts, which are involved in various diseases and individual development. To investigate AS events in MD, RNA-Seq was performed in tumorous spleens (TS), spleens from the survivors (SS) without any lesion after MDV infection, and non-infected chicken spleens (NS). In this study, 32,703 and 25,217 AS events were identified in TS and SS groups with NS group as the control group, and 1198, 1204, and 348 differently expressed (DE) AS events (p-value < 0.05 and FDR < 0.05) were identified in TS vs. NS, TS vs. SS, SS vs. NS, respectively. Additionally, Function enrichment analysis showed that ubiquitin-mediated proteolysis, p53 signaling pathway, and phosphatidylinositol signaling system were significantly enriched (p-value < 0.05). Small structural variations including SNP and indel were analyzed based on RNA-Seq data, and it showed that the TS group possessed more variants on the splice site region than those in SS and NS groups, which might cause more AS events in the TS group. Combined with previous circRNA data, we found that 287 genes could produce both circular and linear RNAs, which suggested these genes were more active in MD lymphoma transformation. This study has expanded the understanding of the MDV infection process and provided new insights for further analysis of resistance/susceptibility mechanisms.
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Fioretti T, Cevenini A, Zanobio M, Raia M, Sarnataro D, Cattaneo F, Ammendola R, Esposito G. Nuclear FGFR2 Interacts with the MLL-AF4 Oncogenic Chimera and Positively Regulates HOXA9 Gene Expression in t(4;11) Leukemia Cells. Int J Mol Sci 2021; 22:ijms22094623. [PMID: 33924850 PMCID: PMC8124917 DOI: 10.3390/ijms22094623] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Revised: 04/22/2021] [Accepted: 04/26/2021] [Indexed: 12/17/2022] Open
Abstract
The chromosomal translocation t(4;11) marks an infant acute lymphoblastic leukemia associated with dismal prognosis. This rearrangement leads to the synthesis of the MLL-AF4 chimera, which exerts its oncogenic activity by upregulating transcription of genes involved in hematopoietic differentiation. Crucial for chimera’s aberrant activity is the recruitment of the AF4/ENL/P-TEFb protein complex. Interestingly, a molecular interactor of AF4 is fibroblast growth factor receptor 2 (FGFR2). We herein analyze the role of FGFR2 in the context of leukemia using t(4;11) leukemia cell lines. We revealed the interaction between MLL-AF4 and FGFR2 by immunoprecipitation, western blot, and immunofluorescence experiments; we also tested the effects of FGFR2 knockdown, FGFR2 inhibition, and FGFR2 stimulation on the expression of the main MLL-AF4 target genes, i.e., HOXA9 and MEIS1. Our results show that FGFR2 and MLL-AF4 interact in the nucleus of leukemia cells and that FGFR2 knockdown, which is associated with decreased expression of HOXA9 and MEIS1, impairs the binding of MLL-AF4 to the HOXA9 promoter. We also show that stimulation of leukemia cells with FGF2 increases nuclear level of FGFR2 in its phosphorylated form, as well as HOXA9 and MEIS1 expression. In contrast, preincubation with the ATP-mimetic inhibitor PD173074, before FGF2 stimulation, reduced FGFR2 nuclear amount and HOXA9 and MEIS1 transcript level, thereby indicating that MLL-AF4 aberrant activity depends on the nuclear availability of FGFR2. Overall, our study identifies FGFR2 as a new and promising therapeutic target in t(4;11) leukemia.
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Affiliation(s)
- Tiziana Fioretti
- CEINGE Advanced Biotechnologies s.c. a r.l., via G. Salvatore, 486, 80145 Naples, Italy; (T.F.); (A.C.); (M.R.); (D.S.)
| | - Armando Cevenini
- CEINGE Advanced Biotechnologies s.c. a r.l., via G. Salvatore, 486, 80145 Naples, Italy; (T.F.); (A.C.); (M.R.); (D.S.)
- Department of Molecular Medicine and Medical Biotechnologies, University of Naples Federico II, Via S. Pansini, 5, 80131 Naples, Italy; (M.Z.); (F.C.); (R.A.)
| | - Mariateresa Zanobio
- Department of Molecular Medicine and Medical Biotechnologies, University of Naples Federico II, Via S. Pansini, 5, 80131 Naples, Italy; (M.Z.); (F.C.); (R.A.)
| | - Maddalena Raia
- CEINGE Advanced Biotechnologies s.c. a r.l., via G. Salvatore, 486, 80145 Naples, Italy; (T.F.); (A.C.); (M.R.); (D.S.)
| | - Daniela Sarnataro
- CEINGE Advanced Biotechnologies s.c. a r.l., via G. Salvatore, 486, 80145 Naples, Italy; (T.F.); (A.C.); (M.R.); (D.S.)
- Department of Molecular Medicine and Medical Biotechnologies, University of Naples Federico II, Via S. Pansini, 5, 80131 Naples, Italy; (M.Z.); (F.C.); (R.A.)
| | - Fabio Cattaneo
- Department of Molecular Medicine and Medical Biotechnologies, University of Naples Federico II, Via S. Pansini, 5, 80131 Naples, Italy; (M.Z.); (F.C.); (R.A.)
| | - Rosario Ammendola
- Department of Molecular Medicine and Medical Biotechnologies, University of Naples Federico II, Via S. Pansini, 5, 80131 Naples, Italy; (M.Z.); (F.C.); (R.A.)
| | - Gabriella Esposito
- CEINGE Advanced Biotechnologies s.c. a r.l., via G. Salvatore, 486, 80145 Naples, Italy; (T.F.); (A.C.); (M.R.); (D.S.)
- Department of Molecular Medicine and Medical Biotechnologies, University of Naples Federico II, Via S. Pansini, 5, 80131 Naples, Italy; (M.Z.); (F.C.); (R.A.)
- Correspondence: ; Tel.: +30-0817463146
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3
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The role of reciprocal fusions in MLL-r acute leukemia: studying the chromosomal translocation t(4;11). Oncogene 2021; 40:6093-6102. [PMID: 34489550 PMCID: PMC8530991 DOI: 10.1038/s41388-021-02001-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 08/10/2021] [Accepted: 08/20/2021] [Indexed: 02/08/2023]
Abstract
Leukemia patients bearing the t(4;11)(q21;q23) translocations can be divided into two subgroups: those expressing both reciprocal fusion genes, and those that have only the MLL-AF4 fusion gene. Moreover, a recent study has demonstrated that patients expressing both fusion genes have a better outcome than patients that are expressing the MLL-AF4 fusion protein alone. All this may point to a clonal process where the reciprocal fusion gene AF4-MLL could be lost during disease progression, as this loss may select for a more aggressive type of leukemia. Therefore, we were interested in unraveling the decisive role of the AF4-MLL fusion protein at an early timepoint of disease development. We designed an experimental model system where the MLL-AF4 fusion protein was constitutively expressed, while an inducible AF4-MLL fusion gene was induced for only 48 h. Subsequently, we investigated genome-wide changes by RNA- and ATAC-Seq experiments at distinct timepoints. These analyses revealed that the expression of AF4-MLL for only 48 h was sufficient to significantly change the genomic landscape (transcription and chromatin) even on a longer time scale. Thus, we have to conclude that the AF4-MLL fusion protein works through a hit-and-run mechanism, probably necessary to set up pre-leukemic conditions, but being dispensable for later disease progression.
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4
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HDAC7 is a major contributor in the pathogenesis of infant t(4;11) proB acute lymphoblastic leukemia. Leukemia 2020; 35:2086-2091. [PMID: 33262526 DOI: 10.1038/s41375-020-01097-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Accepted: 11/14/2020] [Indexed: 12/12/2022]
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5
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Bueno C, Calero-Nieto FJ, Wang X, Valdés-Mas R, Gutiérrez-Agüera F, Roca-Ho H, Ayllon V, Real PJ, Arambilet D, Espinosa L, Torres-Ruiz R, Agraz-Doblas A, Varela I, de Boer J, Bigas A, Gottgens B, Marschalek R, Menendez P. Enhanced hemato-endothelial specification during human embryonic differentiation through developmental cooperation between AF4-MLL and MLL-AF4 fusions. Haematologica 2019; 104:1189-1201. [PMID: 30679325 PMCID: PMC6545840 DOI: 10.3324/haematol.2018.202044] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Accepted: 01/21/2019] [Indexed: 12/18/2022] Open
Abstract
The t(4;11)(q21;q23) translocation is associated with high-risk infant pro-B-cell acute lymphoblastic leukemia and arises prenatally during embryonic/fetal hematopoiesis. The developmental/pathogenic contribution of the t(4;11)-resulting MLL-AF4 (MA4) and AF4-MLL (A4M) fusions remains unclear; MA4 is always expressed in patients with t(4;11)+ B-cell acute lymphoblastic leukemia, but the reciprocal fusion A4M is expressed in only half of the patients. Because prenatal leukemogenesis manifests as impaired early hematopoietic differentiation, we took advantage of well-established human embryonic stem cell-based hematopoietic differentiation models to study whether the A4M fusion cooperates with MA4 during early human hematopoietic development. Co-expression of A4M and MA4 strongly promoted the emergence of hemato-endothelial precursors, both endothelial- and hemogenic-primed. Double fusion-expressing hemato-endothelial precursors specified into significantly higher numbers of both hematopoietic and endothelial-committed cells, irrespective of the differentiation protocol used and without hijacking survival/proliferation. Functional analysis of differentially expressed genes and differentially enriched H3K79me3 genomic regions by RNA-sequencing and H3K79me3 chromatin immunoprecipitation-sequencing, respectively, confirmed a hematopoietic/endothelial cell differentiation signature in double fusion-expressing hemato-endothelial precursors. Importantly, chromatin immunoprecipitation-sequencing analysis revealed a significant enrichment of H3K79 methylated regions specifically associated with HOX-A cluster genes in double fusion-expressing differentiating hematopoietic cells. Overall, these results establish a functional and molecular cooperation between MA4 and A4M fusions during human hematopoietic development.
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Affiliation(s)
- Clara Bueno
- Josep Carreras Leukemia Research Institute and Department of Biomedicine, School of Medicine, University of Barcelona, Spain
- Centro de Investigación Biomédica en Red de Cáncer (CIBER-ONC), ISCIII, Barcelona, Spain
| | - Fernando J Calero-Nieto
- Department of Hematology, Cambridge Institute for Medical Research and Wellcome Trust-Medical Research Council Cambridge Stem Cell Institute, University of Cambridge, UK
| | - Xiaonan Wang
- Department of Hematology, Cambridge Institute for Medical Research and Wellcome Trust-Medical Research Council Cambridge Stem Cell Institute, University of Cambridge, UK
| | | | - Francisco Gutiérrez-Agüera
- Josep Carreras Leukemia Research Institute and Department of Biomedicine, School of Medicine, University of Barcelona, Spain
| | - Heleia Roca-Ho
- Josep Carreras Leukemia Research Institute and Department of Biomedicine, School of Medicine, University of Barcelona, Spain
| | - Veronica Ayllon
- GENyO, Centre for Genomics and Oncological Research, Pfizer/University of Granada/Andalusian Regional Government and University of Granada, Department of Biochemistry and Molecular Biology, Granada, Spain
| | - Pedro J Real
- GENyO, Centre for Genomics and Oncological Research, Pfizer/University of Granada/Andalusian Regional Government and University of Granada, Department of Biochemistry and Molecular Biology, Granada, Spain
| | - David Arambilet
- Programa de Cáncer, Instituto Hospital del Mar de Investigaciones Médicas. Barcelona. Spain
| | - Lluis Espinosa
- Programa de Cáncer, Instituto Hospital del Mar de Investigaciones Médicas. Barcelona. Spain
- Centro de Investigación Biomédica en Red de Cáncer (CIBER-ONC), ISCIII, Barcelona, Spain
| | - Raul Torres-Ruiz
- Josep Carreras Leukemia Research Institute and Department of Biomedicine, School of Medicine, University of Barcelona, Spain
| | - Antonio Agraz-Doblas
- Josep Carreras Leukemia Research Institute and Department of Biomedicine, School of Medicine, University of Barcelona, Spain
- Instituto de Biomedicina y Biotecnología de Cantabria (CSIC-UC-Sodercan), Departamento de Biología Molecular, Universidad de Cantabria, Santander, Spain
| | - Ignacio Varela
- Instituto de Biomedicina y Biotecnología de Cantabria (CSIC-UC-Sodercan), Departamento de Biología Molecular, Universidad de Cantabria, Santander, Spain
| | - Jasper de Boer
- Cancer Section, UCL Great Ormond Street Institute of Child Health, London, UK
| | - Anna Bigas
- Programa de Cáncer, Instituto Hospital del Mar de Investigaciones Médicas. Barcelona. Spain
- Centro de Investigación Biomédica en Red de Cáncer (CIBER-ONC), ISCIII, Barcelona, Spain
| | - Bertie Gottgens
- Department of Hematology, Cambridge Institute for Medical Research and Wellcome Trust-Medical Research Council Cambridge Stem Cell Institute, University of Cambridge, UK
| | - Rolf Marschalek
- Institute of Pharmaceutical Biology, Goethe-University, Frankfurt, Germany
| | - Pablo Menendez
- Josep Carreras Leukemia Research Institute and Department of Biomedicine, School of Medicine, University of Barcelona, Spain
- Centro de Investigación Biomédica en Red de Cáncer (CIBER-ONC), ISCIII, Barcelona, Spain
- Instituciò Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Spain
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Agraz-Doblas A, Bueno C, Bashford-Rogers R, Roy A, Schneider P, Bardini M, Ballerini P, Cazzaniga G, Moreno T, Revilla C, Gut M, Valsecchi MG, Roberts I, Pieters R, De Lorenzo P, Varela I, Menendez P, Stam RW. Unraveling the cellular origin and clinical prognostic markers of infant B-cell acute lymphoblastic leukemia using genome-wide analysis. Haematologica 2019; 104:1176-1188. [PMID: 30679323 PMCID: PMC6545849 DOI: 10.3324/haematol.2018.206375] [Citation(s) in RCA: 63] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Accepted: 12/20/2018] [Indexed: 02/06/2023] Open
Abstract
B-cell acute lymphoblastic leukemia is the commonest childhood cancer. In infants, B-cell acute lymphoblastic leukemia remains fatal, especially in patients with t(4;11), present in ~80% of cases. The pathogenesis of t(4;11)/KMT2A-AFF1+ (MLL-AF4+) infant B-cell acute lymphoblastic leukemia remains difficult to model, and the pathogenic contribution in cancer of the reciprocal fusions resulting from derivative translocated-chromosomes remains obscure. Here, “multi-layered” genome-wide analyses and validation were performed on a total of 124 de novo cases of infant B-cell acute lymphoblastic leukemia uniformly diagnosed and treated according to the Interfant 99/06 protocol. These patients showed the most silent mutational landscape reported so far for any sequenced pediatric cancer. Recurrent mutations were exclusively found in K-RAS and N-RAS, were subclonal and were frequently lost at relapse, despite a larger number of non-recurrent/non-silent mutations. Unlike non-MLL-rearranged B-cell acute lymphoblastic leukemias, B-cell receptor repertoire analysis revealed minor, non-expanded B-cell clones in t(4;11)+ infant B-cell acute lymphoblastic leukemia, and RNA-sequencing showed transcriptomic similarities between t(4;11)+ infant B-cell acute lymphoblastic leukemias and the most immature human fetal liver hematopoietic stem and progenitor cells, confirming a “pre-VDJ” fetal cellular origin for both t(4;11) and RASmut. The reciprocal fusion AF4-MLL was expressed in only 45% (19/43) of the t(4;11)+ patients, and HOXA cluster genes are exclusively expressed in AF4-MLL-expressing patients. Importantly, AF4-MLL/HOXA-expressing patients had a significantly better 4-year event-free survival (62.4% vs. 11.7%, P=0.001), and overall survival (73.7 vs. 25.2%, P=0.016). AF4-MLL expression retained its prognostic significance when analyzed in a Cox model adjusting for risk stratification according to the Interfant-06 protocol based on age at diagnosis, white blood cell count and response to prednisone. This study has clinical implications for disease outcome and diagnostic risk-stratification of t(4;11)+ infant B-cell acute lymphoblastic leukemia.
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Affiliation(s)
- Antonio Agraz-Doblas
- Instituto de Biomedicina y Biotecnología de Cantabria (IBBTEC), Universidad de Cantabria-CSIC, Santander, Spain.,Josep Carreras Leukemia Research Institute-Campus Clinic, Department of Biomedicine, School of Medicine, University of Barcelona, Spain
| | - Clara Bueno
- Josep Carreras Leukemia Research Institute-Campus Clinic, Department of Biomedicine, School of Medicine, University of Barcelona, Spain
| | | | - Anindita Roy
- Department of Paediatrics, University of Oxford, UK
| | - Pauline Schneider
- Princess Maxima Center for Pediatric Oncology, Utrecht, the Netherlands
| | - Michela Bardini
- Centro Ricerca Tettamanti, Department of Pediatrics, University of Milano Bicocca, Fondazione MBBM, Monza, Italy
| | | | - Gianni Cazzaniga
- Centro Ricerca Tettamanti, Department of Pediatrics, University of Milano Bicocca, Fondazione MBBM, Monza, Italy
| | - Thaidy Moreno
- Instituto de Biomedicina y Biotecnología de Cantabria (IBBTEC), Universidad de Cantabria-CSIC, Santander, Spain
| | - Carlos Revilla
- Instituto de Biomedicina y Biotecnología de Cantabria (IBBTEC), Universidad de Cantabria-CSIC, Santander, Spain
| | - Marta Gut
- CNAG-CRG, Center for Genomic Regulation, Barcelona, Spain.,Universitat Pompeu Fabra, Barcelona, Spain
| | - Maria G Valsecchi
- Interfant Trial Data Center, University of Milano-Bicocca, Monza, Italy
| | - Irene Roberts
- Department of Paediatrics, University of Oxford, UK.,MRC Molecular Haematology Unit, MRC Weatherall Institute of Molecular Medicine, University of Oxford, UK
| | - Rob Pieters
- Princess Maxima Center for Pediatric Oncology, Utrecht, the Netherlands
| | - Paola De Lorenzo
- Interfant Trial Data Center, University of Milano-Bicocca, Monza, Italy
| | - Ignacio Varela
- Instituto de Biomedicina y Biotecnología de Cantabria (IBBTEC), Universidad de Cantabria-CSIC, Santander, Spain
| | - Pablo Menendez
- Josep Carreras Leukemia Research Institute-Campus Clinic, Department of Biomedicine, School of Medicine, University of Barcelona, Spain .,Instituciò Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Spain.,Centro de Investigación Biomédica en Red de Cáncer (CIBERONC), ISCIII, Barcelona, Spain
| | - Ronald W Stam
- Princess Maxima Center for Pediatric Oncology, Utrecht, the Netherlands
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7
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Yang L, Ding L, Liang J, Chen J, Tang Y, Xue H, Gu L, Shen S, Li B, Chen J. Relatively favorable prognosis for MLL-rearranged childhood acute leukemia with reciprocal translocations. Pediatr Blood Cancer 2018; 65:e27266. [PMID: 29943896 DOI: 10.1002/pbc.27266] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Revised: 04/16/2018] [Accepted: 05/10/2018] [Indexed: 12/27/2022]
Abstract
BACKGROUND Mixed-lineage leukemia (MLL) with multifarious partner genes leads to aggressive leukemia with dismal outcomes. METHODS Using panel-based targeted sequencing, we examined 90 cases with MLL-rearranged (MLL-r) childhood acute leukemia, including 55 with acute lymphoblastic leukemia (ALL) and 35 with acute myeloid leukemia (AML). RESULTS MLL breakpoints and complete rearrangements were identified. A total of 37.8% (34/90) of patients displayed a single direct MLL fusion gene, 15.6% (14/90) carried a single reciprocal fusion, and 27.8% (25/90) had both reciprocal MLL fusion alleles. The remaining 17 MLL-r cases exhibited complex translocations with homozygous disruptions on chromosome 11 or two breakpoints on the same MLL allele with a deletion of functional regions. A total of 77 patients (45 ALL and 32 AML) received chemotherapy with a median follow-up of 2.5 years. Unexpectedly, we identified children with reciprocal MLL fusions who exhibited relatively favorable outcomes compared with those in children with complex translocations or a single direct MLL fusion allele (66.1% vs. 24.6% and 27.6%, P = 0.001). Reciprocal MLL fusion may be functionally rescued by a partially truncated MLL protein. CONCLUSION Comprehensive MLL-r analysis by targeted next-generation sequencing can provide detailed molecular information and is helpful for precise stratified treatment and clinical prognosis determination.
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Affiliation(s)
- Liu Yang
- Department of Hematology and Oncology, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Key Laboratory of Pediatric Hematology and Oncology Ministry of Health, Department of Hematology and Oncology, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Lixia Ding
- Key Laboratory of Pediatric Hematology and Oncology Ministry of Health, Department of Hematology and Oncology, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Pediatric Translational Medicine Institute, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Jianwei Liang
- Key Laboratory of Pediatric Hematology and Oncology Ministry of Health, Department of Hematology and Oncology, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Jing Chen
- Department of Hematology and Oncology, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - YanJing Tang
- Department of Hematology and Oncology, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Huiliang Xue
- Department of Hematology and Oncology, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Longjun Gu
- Department of Hematology and Oncology, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Shuhong Shen
- Department of Hematology and Oncology, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Key Laboratory of Pediatric Hematology and Oncology Ministry of Health, Department of Hematology and Oncology, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Benshang Li
- Department of Hematology and Oncology, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Shanghai Ministry of Science and Technology Key Laboratory of Health and Disease Genomics, Chinese National Human Genome Center at Shanghai, Shanghai, China
| | - Jing Chen
- Department of Hematology and Oncology, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Key Laboratory of Pediatric Hematology and Oncology Ministry of Health, Department of Hematology and Oncology, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China
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Lukes J, Potuckova E, Sramkova L, Stary J, Starkova J, Trka J, Votava F, Zuna J, Zaliova M. Two novel fusion genes, AIF1L-ETV6 and ABL1-AIF1L, result together with ETV6-ABL1 from a single chromosomal rearrangement in acute lymphoblastic leukemia with prenatal origin. Genes Chromosomes Cancer 2018; 57:471-477. [PMID: 29726059 DOI: 10.1002/gcc.6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Revised: 04/30/2018] [Accepted: 04/30/2018] [Indexed: 01/19/2023] Open
Abstract
Fusion genes resulting from chromosomal rearrangements represent a hallmark of childhood acute lymphoblastic leukemia (ALL). Unlike more common fusion genes generated via simple reciprocal chromosomal translocations, formation of the ETV6-ABL1 fusion gene requires 3 DNA breaks and usually results from an interchromosomal insertion. We report a child with ALL in which a single interchromosomal insertion led to the formation of ETV6-ABL1 and 2 novel fusion genes: AIF1L-ETV6 and ABL1-AIF1L. We demonstrate the prenatal origin of this complex chromosomal rearrangement, which apparently initiated the leukemogenic process, by successful backtracking of the ETV6-ABL1 fusion into the patient's archived neonatal blood. We cloned coding sequences of AIF1L-ETV6 and ABL1-AIF1L in-frame fusion transcripts from the patient's leukemic blasts and we show that the chimeric protein containing the DNA binding domain of ETV6 is expressed from the AIF1L-ETV6 transcript and localized in both the cytoplasm and nucleus of transfected HEK293T cells. Transcriptomic and genomic profiling of the diagnostic bone marrow sample revealed Ph-like gene expression signature and loss of the IKZF1 and CDKN2A/B genes, the typical genetic lesions accompanying ETV6-ABL1-positive ALL. The prenatal origin of the rearrangement confirms that ETV6-ABL1 is not sufficient to cause overt leukemia, even when combined with the 2 novel fusions. We did not find the AIF1L-ETV6 and ABL1-AIF1L fusions in other ETV6-ABL1-positive ALL. Nevertheless, functional studies would be needed to establish the biological role of AIF1L-ETV6 and ABL1-AIF1L and to determine whether they contribute to leukemogenesis and/or to the final leukemia phenotype.
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Affiliation(s)
- Julius Lukes
- CLIP - Childhood Leukaemia Investigation Prague, Prague, Czech Republic
- Department of Paediatric Haematology and Oncology, Second Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Eliska Potuckova
- CLIP - Childhood Leukaemia Investigation Prague, Prague, Czech Republic
- Department of Paediatric Haematology and Oncology, Second Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Lucie Sramkova
- CLIP - Childhood Leukaemia Investigation Prague, Prague, Czech Republic
- Department of Paediatric Haematology and Oncology, Second Faculty of Medicine, Charles University, Prague, Czech Republic
- University Hospital Motol, Prague, Czech Republic
| | - Jan Stary
- Department of Paediatric Haematology and Oncology, Second Faculty of Medicine, Charles University, Prague, Czech Republic
- University Hospital Motol, Prague, Czech Republic
| | - Julia Starkova
- CLIP - Childhood Leukaemia Investigation Prague, Prague, Czech Republic
- Department of Paediatric Haematology and Oncology, Second Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Jan Trka
- CLIP - Childhood Leukaemia Investigation Prague, Prague, Czech Republic
- Department of Paediatric Haematology and Oncology, Second Faculty of Medicine, Charles University, Prague, Czech Republic
- University Hospital Motol, Prague, Czech Republic
| | - Felix Votava
- Department of Pediatrics, 3rd Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Jan Zuna
- CLIP - Childhood Leukaemia Investigation Prague, Prague, Czech Republic
- Department of Paediatric Haematology and Oncology, Second Faculty of Medicine, Charles University, Prague, Czech Republic
- University Hospital Motol, Prague, Czech Republic
| | - Marketa Zaliova
- CLIP - Childhood Leukaemia Investigation Prague, Prague, Czech Republic
- Department of Paediatric Haematology and Oncology, Second Faculty of Medicine, Charles University, Prague, Czech Republic
- University Hospital Motol, Prague, Czech Republic
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9
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Liu G, Lu X, Kim YM, Wang X, Li S, Liu Y. Simultaneous involvement of 11q23 translocation resulting in chimeric MLL-AFF1 and a second translocation [t (9;21) (p13; p11.2)] in an infant acute lymphoblastic leukemia patient at relapse: A case report. Medicine (Baltimore) 2018; 97:e10874. [PMID: 29794792 PMCID: PMC6392770 DOI: 10.1097/md.0000000000010874] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
RATIONALE Three-way translocations occasionally occur in MLL-AFF1 fusion and other fusion gene. However, the complex chromosomal rearrangements in the study were the first report. PATIENT CONCERNS We present novel cryptic and complex chromosomal rearrangements [der (21) t (9; 21) (p13; p11.2)] in an infant patient with relapsed acute lymphoblastic leukemia (ALL). DIAGNOSES The diagnosis was based on morphologic, cytochemical, and immunophenotypic criteria proposed by the French-American-British Committee, and karyotype, fluorescence in situ hybridization, array comparative genomic hybridization. INTERVENTIONS The patient was given chemotherapy with standard protocol for ALL. OUTCOMES The patient had unfavorable prognostic outcome based on the cytogenetic and molecular cytogenetic markers. After short remission, the patient relapsed. LESSONS MLL-AFF1, resulting from t(4;11)(q21;q23), is regarded as the hallmark of infant t(4;11) pre-B/mixed B-ALL. It is associated with a dismal prognosis and the multiple-way translocation involving chromosomes 4, 11 and 11 may function as an enhancer.
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Affiliation(s)
- Guangming Liu
- Department of Gastroenterology, The First Hospital of Jilin University, Changchun, People's Republic of China
- Department of Pediatrics, University of Oklahoma Health Sciences Center, Oklahoma City, OK
| | - Xianglan Lu
- Department of Pediatrics, University of Oklahoma Health Sciences Center, Oklahoma City, OK
| | - Young Mi Kim
- Department of Pediatrics, University of Oklahoma Health Sciences Center, Oklahoma City, OK
| | - Xianfu Wang
- Department of Pediatrics, University of Oklahoma Health Sciences Center, Oklahoma City, OK
| | - Shibo Li
- Department of Pediatrics, University of Oklahoma Health Sciences Center, Oklahoma City, OK
| | - Yuanyuan Liu
- Department of Gastroenterology, The First Hospital of Jilin University, Changchun, People's Republic of China
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Malouf C, Ottersbach K. Molecular processes involved in B cell acute lymphoblastic leukaemia. Cell Mol Life Sci 2018; 75:417-446. [PMID: 28819864 PMCID: PMC5765206 DOI: 10.1007/s00018-017-2620-z] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Revised: 08/01/2017] [Accepted: 08/04/2017] [Indexed: 12/19/2022]
Abstract
B cell leukaemia is one of the most frequent malignancies in the paediatric population, but also affects a significant proportion of adults in developed countries. The majority of infant and paediatric cases initiate the process of leukaemogenesis during foetal development (in utero) through the formation of a chromosomal translocation or the acquisition/deletion of genetic material (hyperdiploidy or hypodiploidy, respectively). This first genetic insult is the major determinant for the prognosis and therapeutic outcome of patients. B cell leukaemia in adults displays similar molecular features as its paediatric counterpart. However, since this disease is highly represented in the infant and paediatric population, this review will focus on this demographic group and summarise the biological, clinical and epidemiological knowledge on B cell acute lymphoblastic leukaemia of four well characterised subtypes: t(4;11) MLL-AF4, t(12;21) ETV6-RUNX1, t(1;19) E2A-PBX1 and t(9;22) BCR-ABL1.
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Affiliation(s)
- Camille Malouf
- MRC Centre for Regenerative Medicine, The University of Edinburgh, 5 Little France Drive, Edinburgh, EH16 4UU, UK
| | - Katrin Ottersbach
- MRC Centre for Regenerative Medicine, The University of Edinburgh, 5 Little France Drive, Edinburgh, EH16 4UU, UK.
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11
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Rontauroli S, Norfo R, Pennucci V, Zini R, Ruberti S, Bianchi E, Salati S, Prudente Z, Rossi C, Rosti V, Guglielmelli P, Barosi G, Vannucchi A, Tagliafico E, Manfredini R. miR-494-3p overexpression promotes megakaryocytopoiesis in primary myelofibrosis hematopoietic stem/progenitor cells by targeting SOCS6. Oncotarget 2017; 8:21380-21397. [PMID: 28423484 PMCID: PMC5400591 DOI: 10.18632/oncotarget.15226] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2016] [Accepted: 01/23/2017] [Indexed: 11/25/2022] Open
Abstract
Primary myelofibrosis (PMF) is a chronic Philadelphia-negative myeloproliferative neoplasm characterized by hematopoietic stem cell-derived clonal myeloproliferation, involving especially the megakaryocyte lineage. To better characterize how the altered expression of microRNAs might contribute to PMF pathogenesis, we have previously performed the integrative analysis of gene and microRNA expression profiles of PMF hematopoietic stem/progenitor cells (HSPCs), which allowed us to identify miR-494-3p as the upregulated microRNA predicted to target the highest number of downregulated mRNAs.To elucidate the role of miR-494-3p in hematopoietic differentiation, in the present study we demonstrated that miR-494-3p enforced expression in normal HSPCs promotes megakaryocytopoiesis. Gene expression profiling upon miR-494-3p overexpression allowed the identification of genes commonly downregulated both after microRNA overexpression and in PMF CD34+ cells. Among them, suppressor of cytokine signaling 6 (SOCS6) was confirmed to be a miR-494-3p target by luciferase assay. Western blot analysis showed reduced level of SOCS6 protein as well as STAT3 activation in miR-494-3p overexpressing cells. Furthermore, transient inhibition of SOCS6 expression in HSPCs demonstrated that SOCS6 silencing stimulates megakaryocytopoiesis, mimicking the phenotypic effects observed upon miR-494-3p overexpression. Finally, to disclose the contribution of miR-494-3p upregulation to PMF pathogenesis, we performed inhibition experiments in PMF HSPCs, which showed that miR-494-3p silencing led to SOCS6 upregulation and impaired megakaryocyte differentiation.Taken together, our results describe for the first time the role of miR-494-3p during normal HSPC differentiation and suggest that its increased expression, and the subsequent downregulation of its target SOCS6, might contribute to the megakaryocyte hyperplasia commonly observed in PMF patients.
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Affiliation(s)
- Sebastiano Rontauroli
- Centre for Regenerative Medicine, Life Sciences Department, University of Modena and Reggio Emilia, Modena, Italy
| | - Ruggiero Norfo
- Centre for Regenerative Medicine, Life Sciences Department, University of Modena and Reggio Emilia, Modena, Italy
| | - Valentina Pennucci
- Centre for Regenerative Medicine, Life Sciences Department, University of Modena and Reggio Emilia, Modena, Italy
| | - Roberta Zini
- Centre for Regenerative Medicine, Life Sciences Department, University of Modena and Reggio Emilia, Modena, Italy
| | - Samantha Ruberti
- Centre for Regenerative Medicine, Life Sciences Department, University of Modena and Reggio Emilia, Modena, Italy
| | - Elisa Bianchi
- Centre for Regenerative Medicine, Life Sciences Department, University of Modena and Reggio Emilia, Modena, Italy
| | - Simona Salati
- Centre for Regenerative Medicine, Life Sciences Department, University of Modena and Reggio Emilia, Modena, Italy
| | - Zelia Prudente
- Centre for Regenerative Medicine, Life Sciences Department, University of Modena and Reggio Emilia, Modena, Italy
| | - Chiara Rossi
- Centre for Regenerative Medicine, Life Sciences Department, University of Modena and Reggio Emilia, Modena, Italy
| | - Vittorio Rosti
- Center for The Study of Myelofibrosis, Biotechnology Research Area, IRCCS Policlinico S. Matteo Foundation, Pavia, Italy
| | - Paola Guglielmelli
- CRIMM-Center for Research and Innovation for Myeloproliferative Neoplasms, AOU Careggi, and Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
| | - Giovanni Barosi
- Center for The Study of Myelofibrosis, Biotechnology Research Area, IRCCS Policlinico S. Matteo Foundation, Pavia, Italy
| | - Alessandro Vannucchi
- CRIMM-Center for Research and Innovation for Myeloproliferative Neoplasms, AOU Careggi, and Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
| | - Enrico Tagliafico
- Center for Genome Research, University of Modena and Reggio Emilia, Modena, Italy
| | - Rossella Manfredini
- Centre for Regenerative Medicine, Life Sciences Department, University of Modena and Reggio Emilia, Modena, Italy
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12
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Hiwatari M, Seki M, Akahoshi S, Yoshida K, Miyano S, Shiraishi Y, Tanaka H, Chiba K, Ogawa S, Takita J. Molecular studies reveal MLL-MLLT10/AF10 and ARID5B-MLL gene fusions displaced in a case of infantile acute lymphoblastic leukemia with complex karyotype. Oncol Lett 2017; 14:2295-2299. [PMID: 28781666 PMCID: PMC5530220 DOI: 10.3892/ol.2017.6430] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2016] [Accepted: 05/18/2017] [Indexed: 02/02/2023] Open
Abstract
The present report describes a unique infantile acute lymphoblastic leukemia (ALL) case with cryptic mixed-lineage leukemia (MLL) rearrangements with 11q23 chromosomal translocation. MLL break-apart signals were identified by fluorescence in situ hybridization, and transcriptome sequencing revealed MLL-myeloid/lymphoid or mixed-lineage leukemia; translocated To, 10 (MLLT10)/AF10 fusion transcripts. Analysis also revealed a previously unreported MLLT10/AF10-homeobox protein Mohawk (MKX) transcript, where the 5′ portion of MLLT10/AF10 at 10p12.31 was fused out-of-frame with the 3′ portion of MKX at 10p12.1, which is closely located to MLLT10/AF10. Furthermore, the reciprocal 3′-MLL gene segment was fused in-frame to AT-rich interaction domain (ARID)5B at 10q21. Previously, common allelic variants in ARID5B, which are directly associated with hematopoietic differentiation and development, have been repeatedly and significantly associated with childhood ALL. The heterozygous genotype in ARID5B (RefSNP: rs10821936) increased the risk for leukemia with MLL-rearrangement. In particular, single nucleotide polymorphisms of ARID5B conferred increased risk for MLL-MLLT3/AF9. Based on these findings, the authors propose that while the presence of reciprocal MLL alleles has been detected in this patient, different pathological disease mechanisms may be at play due to individual recombination events.
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Affiliation(s)
- Mitsuteru Hiwatari
- Department of Pediatrics, Graduate School of Medicine, University of Tokyo, Tokyo 113-8655, Japan.,Department of Cell Therapy and Transplantation Medicine, University of Tokyo, Tokyo 113-8655, Japan
| | - Masafumi Seki
- Department of Pediatrics, Graduate School of Medicine, University of Tokyo, Tokyo 113-8655, Japan
| | - Shogo Akahoshi
- Department of Pediatrics, Graduate School of Medicine, University of Tokyo, Tokyo 113-8655, Japan
| | - Kenichi Yoshida
- Department of Pathology and Tumor Biology, Graduate School of Medicine, Kyoto University, Kyoto 606-8501, Japan
| | - Satoru Miyano
- Laboratory of DNA Information Analysis, Human Genome Center, Institute of Medical Science, University of Tokyo, Tokyo 108-8639, Japan.,Laboratory of Sequence Analysis, Human Genome Center, Institute of Medical Science, University of Tokyo, Tokyo 108-8639, Japan
| | - Yuichi Shiraishi
- Laboratory of DNA Information Analysis, Human Genome Center, Institute of Medical Science, University of Tokyo, Tokyo 108-8639, Japan
| | - Hiroko Tanaka
- Laboratory of Sequence Analysis, Human Genome Center, Institute of Medical Science, University of Tokyo, Tokyo 108-8639, Japan
| | - Kenichi Chiba
- Laboratory of DNA Information Analysis, Human Genome Center, Institute of Medical Science, University of Tokyo, Tokyo 108-8639, Japan
| | - Seishi Ogawa
- Department of Pathology and Tumor Biology, Graduate School of Medicine, Kyoto University, Kyoto 606-8501, Japan
| | - Junko Takita
- Department of Pediatrics, Graduate School of Medicine, University of Tokyo, Tokyo 113-8655, Japan
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13
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Mouse models of MLL leukemia: recapitulating the human disease. Blood 2017; 129:2217-2223. [PMID: 28179274 DOI: 10.1182/blood-2016-10-691428] [Citation(s) in RCA: 74] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2016] [Accepted: 02/03/2017] [Indexed: 12/13/2022] Open
Abstract
Chromosome translocations involving the mixed lineage leukemia (MLL) gene fuse it in frame with multiple partner genes creating novel fusion proteins (MLL-FPs) that cause aggressive acute leukemias in humans. Animal models of human disease are important for the exploration of underlying disease mechanisms as well as for testing novel therapeutic approaches. Patients carrying MLL-FPs have very few cooperating mutations, making MLL-FP driven leukemias ideal for animal modeling. The fact that the MLL-FP is the main driver mutation has allowed for a wide range of different experimental model systems designed to explore different aspects of MLL-FP leukemogenesis. In addition, MLL-FP driven acute myeloid leukemia (AML) in mice is often used as a general model for AML. This review provides an overview of different MLL-FP mouse model systems and discusses how well they have recapitulated aspects of the human disease as well as highlights the biological insights each model has provided into MLL-FP leukemogenesis. Many promising new drugs fail in the early stages of clinical trials. Lessons learned from past and present MLL-FP models may serve as a paradigm for designing more flexible and dynamic preclinical models for these as well as other acute leukemias.
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14
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Godfrey L, Kerry J, Thorne R, Repapi E, Davies JOJ, Tapia M, Ballabio E, Hughes JR, Geng H, Konopleva M, Milne TA. MLL-AF4 binds directly to a BCL-2 specific enhancer and modulates H3K27 acetylation. Exp Hematol 2016; 47:64-75. [PMID: 27856324 PMCID: PMC5333536 DOI: 10.1016/j.exphem.2016.11.003] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Revised: 10/21/2016] [Accepted: 11/02/2016] [Indexed: 11/15/2022]
Abstract
Survival rates for children and adults carrying mutations in the Mixed Lineage Leukemia (MLL) gene continue to have a very poor prognosis. The most common MLL mutation in acute lymphoblastic leukemia is the t(4;11)(q21;q23) chromosome translocation that fuses MLL in-frame with the AF4 gene producing MLL-AF4 and AF4-MLL fusion proteins. Previously, we found that MLL-AF4 binds to the BCL-2 gene and directly activates it through DOT1L recruitment and increased H3K79me2/3 levels. In the study described here, we performed a detailed analysis of MLL-AF4 regulation of the entire BCL-2 family. By measuring nascent RNA production in MLL-AF4 knockdowns, we found that of all the BCL-2 family genes, MLL-AF4 directly controls the active transcription of both BCL-2 and MCL-1 and also represses BIM via binding of the polycomb group repressor 1 (PRC1) complex component CBX8. We further analyzed MLL-AF4 activation of the BCL-2 gene using Capture-C and identified a BCL-2-specific enhancer, consisting of two clusters of H3K27Ac at the 3' end of the gene. Loss of MLL-AF4 activity results in a reduction of H3K79me3 levels in the gene body and H3K27Ac levels at the 3' BCL-2 enhancer, revealing a novel regulatory link between these two histone marks and MLL-AF4-mediated activation of BCL-2.
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Affiliation(s)
- Laura Godfrey
- Weatherall Institute of Molecular Medicine, MRC Molecular Haematology Unit, University of Oxford, Headington, Oxford, UK
| | - Jon Kerry
- Weatherall Institute of Molecular Medicine, MRC Molecular Haematology Unit, University of Oxford, Headington, Oxford, UK
| | - Ross Thorne
- Weatherall Institute of Molecular Medicine, MRC Molecular Haematology Unit, University of Oxford, Headington, Oxford, UK
| | - Emmanouela Repapi
- Weatherall Institute of Molecular Medicine, Computational Biology Research Group, University of Oxford, Headington, Oxford, UK
| | - James O J Davies
- Weatherall Institute of Molecular Medicine, MRC Molecular Haematology Unit, University of Oxford, Headington, Oxford, UK
| | - Marta Tapia
- Weatherall Institute of Molecular Medicine, MRC Molecular Haematology Unit, University of Oxford, Headington, Oxford, UK
| | - Erica Ballabio
- Weatherall Institute of Molecular Medicine, MRC Molecular Haematology Unit, University of Oxford, Headington, Oxford, UK
| | - Jim R Hughes
- Weatherall Institute of Molecular Medicine, MRC Molecular Haematology Unit, University of Oxford, Headington, Oxford, UK
| | - Huimin Geng
- Department of Laboratory Medicine, University of California San Francisco, San Francisco, CA
| | - Marina Konopleva
- Department of Leukemia, University of Texas MD Anderson Cancer Center, Houston, TX
| | - Thomas A Milne
- Weatherall Institute of Molecular Medicine, MRC Molecular Haematology Unit, University of Oxford, Headington, Oxford, UK.
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15
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Revisiting the biology of infant t(4;11)/MLL-AF4+ B-cell acute lymphoblastic leukemia. Blood 2015; 126:2676-85. [PMID: 26463423 DOI: 10.1182/blood-2015-09-667378] [Citation(s) in RCA: 82] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Accepted: 09/30/2015] [Indexed: 02/06/2023] Open
Abstract
Infant B-cell acute lymphoblastic leukemia (B-ALL) accounts for 10% of childhood ALL. The genetic hallmark of most infant B-ALL is chromosomal rearrangements of the mixed-lineage leukemia (MLL) gene. Despite improvement in the clinical management and survival (∼85-90%) of childhood B-ALL, the outcome of infants with MLL-rearranged (MLL-r) B-ALL remains dismal, with overall survival <35%. Among MLL-r infant B-ALL, t(4;11)+ patients harboring the fusion MLL-AF4 (MA4) display a particularly poor prognosis and a pro-B/mixed phenotype. Studies in monozygotic twins and archived blood spots have provided compelling evidence of a single cell of prenatal origin as the target for MA4 fusion, explaining the brief leukemia latency. Despite its aggressiveness and short latency, current progress on its etiology, pathogenesis, and cellular origin is limited as evidenced by the lack of mouse/human models recapitulating the disease phenotype/latency. We propose this is because infant cancer is from an etiologic and pathogenesis standpoint distinct from adult cancer and should be seen as a developmental disease. This is supported by whole-genome sequencing studies suggesting that opposite to the view of cancer as a "multiple-and-sequential-hit" model, t(4;11) alone might be sufficient to spawn leukemia. The stable genome of these patients suggests that, in infant developmental cancer, one "big-hit" might be sufficient for overt disease and supports a key contribution of epigenetics and a prenatal cell of origin during a critical developmental window of stem cell vulnerability in the leukemia pathogenesis. Here, we revisit the biology of t(4;11)+ infant B-ALL with an emphasis on its origin, genetics, and disease models.
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16
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Array-based comparative genomic hybridization detects copy number variations with prognostic relevance in 80% of ALL with normal karyotype or failed chromosome analysis. Leukemia 2015; 30:318-24. [PMID: 26449660 DOI: 10.1038/leu.2015.276] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Revised: 09/09/2015] [Accepted: 09/30/2015] [Indexed: 11/08/2022]
Abstract
Pretreatment cytogenetics is an important parameter for risk stratification and therapy approach in acute lymphoblastic leukemia (ALL). However, in up to 30% of cases, chromosome banding analysis (CBA) fails or reveals a normal karyotype. To characterize the subset of ALL with normal karyotype or failed CBA, we performed fluorescence in situ hybridization (FISH) or PCR for BCR-ABL1 and MLL rearrangements as well as array comparative genomic hybridization (aCGH) in 186 adult patients. We further carried out FISH for MYC in cases with Burkitt leukemia phenotype. FISH or PCR revealed one of the respective rearrangements in 22% of patients. In 80% of cases, copy number variations (CNV) were identified by aCGH. In 22% of cases, all CNV were below the resolution of CBA. On the basis of results of FISH, RT-PCR and aCGH, patients were categorized into three groups. The novel subset of patients with submicroscopic CNV only showed an overall survival at 3 years of 84% compared with 64% for patients classified as adverse abnormalities and 77% for cases with other aberrations (P=0.046). Thus, ALL with non-informative CBA can be further classified by FISH and aCGH providing prognostic information, which may be useful for a more individualized therapy.
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17
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Unraveling the Activation Mechanism of Taspase1 which Controls the Oncogenic AF4-MLL Fusion Protein. EBioMedicine 2015; 2:386-95. [PMID: 26137584 PMCID: PMC4486195 DOI: 10.1016/j.ebiom.2015.04.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2014] [Revised: 04/14/2015] [Accepted: 04/14/2015] [Indexed: 12/11/2022] Open
Abstract
We have recently demonstrated that Taspase1-mediated cleavage of the AF4–MLL oncoprotein results in the formation of a stable multiprotein complex which forms the key event for the onset of acute proB leukemia in mice. Therefore, Taspase1 represents a conditional oncoprotein in the context of t(4;11) leukemia. In this report, we used site-directed mutagenesis to unravel the molecular events by which Taspase1 becomes sequentially activated. Monomeric pro-enzymes form dimers which are autocatalytically processed into the enzymatically active form of Taspase1 (αββα). The active enzyme cleaves only very few target proteins, e.g., MLL, MLL4 and TFIIA at their corresponding consensus cleavage sites (CSTasp1) as well as AF4–MLL in the case of leukemogenic translocation. This knowledge was translated into the design of a dominant-negative mutant of Taspase1 (dnTASP1). As expected, simultaneous expression of the leukemogenic AF4–MLL and dnTASP1 causes the disappearance of the leukemogenic oncoprotein, because the uncleaved AF4–MLL protein (328 kDa) is subject to proteasomal degradation, while the cleaved AF4–MLL forms a stable oncogenic multi-protein complex with a very long half-life. Moreover, coexpression of dnTASP1 with a BFP-CSTasp1-GFP FRET biosensor effectively inhibits cleavage. The impact of our findings on future drug development and potential treatment options for t(4;11) leukemia will be discussed. Taspase1 has coevolved with the Trithorax/MLL protein family. Taspase1 hydrolyzes MLL and few other substrate proteins at consensus cleavage sites. Taspase1 is a conditional oncoprotein in of solid and hematological cancers. Taspase1 is required for the processing of the leukemogenic AF4–MLL fusion protein. Inhibition of Taspase1 might have a great therapeutic potential.
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Ballabio E, Milne TA. Epigenetic control of gene expression in leukemogenesis: Cooperation between wild type MLL and MLL fusion proteins. Mol Cell Oncol 2014; 1:e955330. [PMID: 27308325 PMCID: PMC4905190 DOI: 10.1080/23723548.2014.955330] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2014] [Revised: 07/14/2014] [Accepted: 07/17/2014] [Indexed: 12/17/2022]
Abstract
Although there has been great progress in the treatment of human cancers, especially leukemias, many remain resistant to treatment. A major current focus is the development of so-called epigenetic drugs. Epigenetic states are stable enough to persist through multiple cell divisions, but by their very nature are reversible and thus are amenable to therapeutic manipulation. Exciting work in this area has produced a new breed of highly specific small molecules designed to inhibit epigenetic proteins, some of which have entered clinical trials. The current and future development of epigenetic drugs is greatly aided by highly detailed information about normal and aberrant epigenetic changes at the molecular level. In this review we focus on a class of aggressive acute leukemias caused by mutations in the Mixed Lineage Leukemia (MLL) gene. We provide an overview of how detailed molecular analysis of MLL leukemias has provided several early-stage epigenetic drugs and propose that further study of MLL leukemogenesis may continue to provide molecular details that potentially have a wider range of applications in human cancers.
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Affiliation(s)
- Erica Ballabio
- MRC Molecular Hematology Unit; Weatherall Institute of Molecular Medicine; University of Oxford ; Oxford, UK
| | - Thomas A Milne
- MRC Molecular Hematology Unit; Weatherall Institute of Molecular Medicine; University of Oxford ; Oxford, UK
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19
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Hatzipantelis E, Pana ZD, Papageorgiou T, Hatzistilianou M, Athanasiadou A, Sarafidis K, Tsotoulidou V, Papaioannou G, Athanassiadou F. Congenital acute lymphoblastic leukemia case with a novel t(2:4:11) (p21:q21:q23) translocation. Pediatr Hematol Oncol 2014; 31:178-80. [PMID: 24274464 DOI: 10.3109/08880018.2013.838813] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Affiliation(s)
- Emmanuel Hatzipantelis
- Pediatric Hematology Oncology Unit, 2nd Pediatric Department of Aristotle University, AHEPA General Hospital, Thessaloniki, Greece
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20
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Tuborgh A, Meyer C, Marschalek R, Preiss B, Hasle H, Kjeldsen E. Complex Three-Way Translocation Involving MLL, ELL, RREB1, and CMAHP Genes in an Infant with Acute Myeloid Leukemia and t(6;19;11)(p22.2;p13.1;q23.3). Cytogenet Genome Res 2013; 141:7-15. [DOI: 10.1159/000351224] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/22/2013] [Indexed: 11/19/2022] Open
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21
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Binato R, Meyer C, Macedo-Silva ML, Garcia D, Figueiredo A, Hofmann J, Vieira TP, Abdelhay E, Marschalek R. Analyzing acute leukemia patients with complex MLL rearrangements by a sequential LDI-PCR approach. Cancer Lett 2013; 338:249-54. [PMID: 23562474 DOI: 10.1016/j.canlet.2013.03.029] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2013] [Revised: 03/22/2013] [Accepted: 03/26/2013] [Indexed: 10/27/2022]
Abstract
Translocations involving MLL gene are common among children with acute leukemias. Most importantly, the presence of a given MLL fusion partner dictates the outcome of patients. Patients with complex MLL rearrangements, e.g. three-way translocations could be related to a poor clinical outcome. For this purpose, we characterize 5 childhood patients with three-way translocations involving MLL gene. By LDI-PCR we identified 15 out of 17 fusion alleles and determined the localization of these breakpoints. In all cases at least one functional MLL fusion allele was present. In addition, patients displayed a remaining 3'-MLL allele that allow in principle the expression of the MLL* protein variant.
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Affiliation(s)
- Renata Binato
- Stem Cell Laboratory, Bone Marrow Transplantation Unit, National Cancer Institute (INCA), Rio de Janeiro, RJ, Brazil.
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Wilkinson A, Ballabio E, Geng H, North P, Tapia M, Kerry J, Biswas D, Roeder R, Allis C, Melnick A, de Bruijn M, Milne T. RUNX1 is a key target in t(4;11) leukemias that contributes to gene activation through an AF4-MLL complex interaction. Cell Rep 2013; 3:116-27. [PMID: 23352661 PMCID: PMC3607232 DOI: 10.1016/j.celrep.2012.12.016] [Citation(s) in RCA: 113] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2012] [Revised: 11/08/2012] [Accepted: 12/26/2012] [Indexed: 12/22/2022] Open
Abstract
The Mixed Lineage Leukemia (MLL) protein is an important epigenetic regulator required for the maintenance of gene activation during development. MLL chromosomal translocations produce novel fusion proteins that cause aggressive leukemias in humans. Individual MLL fusion proteins have distinct leukemic phenotypes even when expressed in the same cell type, but how this distinction is delineated on a molecular level is poorly understood. Here, we highlight a unique molecular mechanism whereby the RUNX1 gene is directly activated by MLL-AF4 and the RUNX1 protein interacts with the product of the reciprocal AF4-MLL translocation. These results support a mechanism of transformation whereby two oncogenic fusion proteins cooperate by activating a target gene and then modulating the function of its downstream product.
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Affiliation(s)
- Adam C. Wilkinson
- MRC Molecular Haematology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford OX3 9DS, UK
| | - Erica Ballabio
- MRC Molecular Haematology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford OX3 9DS, UK
| | - Huimin Geng
- Departments of Medicine/Hematology and Oncology Division, Weill Medical College of Cornell University, New York, NY, 10065, USA
- Institute for Computational Biomedicine, Weill Medical College of Cornell University, New York, NY, 10065, USA
- Department of Laboratory Medicine, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Phillip North
- MRC Molecular Haematology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford OX3 9DS, UK
| | - Marta Tapia
- MRC Molecular Haematology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford OX3 9DS, UK
| | - Jon Kerry
- MRC Molecular Haematology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford OX3 9DS, UK
| | - Debabrata Biswas
- Laboratory of Biochemistry and Molecular Biology, The Rockefeller University, New York, NY 10065, USA
| | - Robert G. Roeder
- Laboratory of Biochemistry and Molecular Biology, The Rockefeller University, New York, NY 10065, USA
| | - C. David Allis
- Laboratory of Chromatin Biology and Epigenetics, The Rockefeller University, New York, NY 10065, USA
| | - Ari Melnick
- Departments of Medicine/Hematology and Oncology Division, Weill Medical College of Cornell University, New York, NY, 10065, USA
- Department of Pharmacology, Weill Medical College of Cornell University, New York, NY, 10065, USA
| | - Marella F.T.R. de Bruijn
- MRC Molecular Haematology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford OX3 9DS, UK
| | - Thomas A. Milne
- MRC Molecular Haematology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford OX3 9DS, UK
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Al‐Shehhi H, Konn ZJ, Schwab CJ, Erhorn A, Barber KE, Wright SL, Gabriel AS, Harrison CJ, Moorman AV. Abnormalities of the der(12)t(12;21) in
ETV6‐RUNX1
acute lymphoblastic leukemia. Genes Chromosomes Cancer 2012; 52:202-13. [DOI: 10.1002/gcc.22021] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2012] [Revised: 09/18/2012] [Accepted: 09/19/2012] [Indexed: 11/06/2022] Open
Affiliation(s)
- Halima Al‐Shehhi
- Leukaemia Research Cytogenetics Group, Northern Institute for Cancer Research, Newcastle University, Newcastle‐upon‐Tyne, UK
| | - Zoe J. Konn
- Leukaemia Research Cytogenetics Group, Northern Institute for Cancer Research, Newcastle University, Newcastle‐upon‐Tyne, UK
| | - Claire J. Schwab
- Leukaemia Research Cytogenetics Group, Northern Institute for Cancer Research, Newcastle University, Newcastle‐upon‐Tyne, UK
| | - Amy Erhorn
- Leukaemia Research Cytogenetics Group, Northern Institute for Cancer Research, Newcastle University, Newcastle‐upon‐Tyne, UK
| | - Kerry E. Barber
- Leukaemia Research Cytogenetics Group, Northern Institute for Cancer Research, Newcastle University, Newcastle‐upon‐Tyne, UK
| | - Sarah L. Wright
- Leukaemia Research Cytogenetics Group, Northern Institute for Cancer Research, Newcastle University, Newcastle‐upon‐Tyne, UK
| | - Alem S. Gabriel
- Leukaemia Research Cytogenetics Group, Northern Institute for Cancer Research, Newcastle University, Newcastle‐upon‐Tyne, UK
| | - Christine J. Harrison
- Leukaemia Research Cytogenetics Group, Northern Institute for Cancer Research, Newcastle University, Newcastle‐upon‐Tyne, UK
| | - Anthony V. Moorman
- Leukaemia Research Cytogenetics Group, Northern Institute for Cancer Research, Newcastle University, Newcastle‐upon‐Tyne, UK
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24
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Ballabio E, Milne TA. Molecular and Epigenetic Mechanisms of MLL in Human Leukemogenesis. Cancers (Basel) 2012; 4:904-44. [PMID: 24213472 PMCID: PMC3712720 DOI: 10.3390/cancers4030904] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2012] [Revised: 08/31/2012] [Accepted: 09/04/2012] [Indexed: 01/20/2023] Open
Abstract
Epigenetics is often defined as the study of heritable changes in gene expression or chromosome stability that don’t alter the underlying DNA sequence. Epigenetic changes are established through multiple mechanisms that include DNA methylation, non-coding RNAs and the covalent modification of specific residues on histone proteins. It is becoming clear not only that aberrant epigenetic changes are common in many human diseases such as leukemia, but that these changes by their very nature are malleable, and thus are amenable to treatment. Epigenetic based therapies have so far focused on the use of histone deacetylase (HDAC) inhibitors and DNA methyltransferase inhibitors, which tend to have more general and widespread effects on gene regulation in the cell. However, if a unique molecular pathway can be identified, diseases caused by epigenetic mechanisms are excellent candidates for the development of more targeted therapies that focus on specific gene targets, individual binding domains, or specific enzymatic activities. Designing effective targeted therapies depends on a clear understanding of the role of epigenetic mutations during disease progression. The Mixed Lineage Leukemia (MLL) protein is an example of a developmentally important protein that controls the epigenetic activation of gene targets in part by methylating histone 3 on lysine 4. MLL is required for normal development, but is also mutated in a subset of aggressive human leukemias and thus provides a useful model for studying the link between epigenetic cell memory and human disease. The most common MLL mutations are chromosome translocations that fuse the MLL gene in frame with partner genes creating novel fusion proteins. In this review, we summarize recent work that argues MLL fusion proteins could function through a single molecular pathway, but we also highlight important data that suggests instead that multiple independent mechanisms underlie MLL mediated leukemogenesis.
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Affiliation(s)
- Erica Ballabio
- MRC Molecular Haematology Unit, Weatherall Institute of Molecular Medicine, John Radcliffe Hospital Headington, Oxford OX3 9DS, UK.
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25
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Cho SY, Park TS, Oh SH, Cho EH, Oh D, Huh JY, Marschalek R, Meyer C. Genomic analysis of a four-way t(4;11;22;10) associated with MLL-AF4 in an adult acute lymphoblastic leukemia. Ann Hematol 2011; 91:977-9. [PMID: 22086294 DOI: 10.1007/s00277-011-1364-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2011] [Accepted: 10/26/2011] [Indexed: 01/12/2023]
MESH Headings
- Adult
- Base Sequence
- Chromosomes, Human, Pair 10/genetics
- Chromosomes, Human, Pair 11/genetics
- Chromosomes, Human, Pair 22/genetics
- Chromosomes, Human, Pair 4/genetics
- Cytogenetic Analysis
- Genome, Human
- Humans
- Male
- Molecular Sequence Data
- Myeloid-Lymphoid Leukemia Protein/genetics
- Oncogene Proteins, Fusion/genetics
- Precursor Cell Lymphoblastic Leukemia-Lymphoma/diagnosis
- Precursor Cell Lymphoblastic Leukemia-Lymphoma/genetics
- Translocation, Genetic
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26
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Fine structure of translocation breakpoints within the major breakpoint region in BCR-ABL1-positive leukemias. DNA Repair (Amst) 2011; 10:1131-7. [DOI: 10.1016/j.dnarep.2011.08.010] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2011] [Revised: 08/09/2011] [Accepted: 08/19/2011] [Indexed: 02/06/2023]
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27
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Enforced expression of MLL-AF4 fusion in cord blood CD34+ cells enhances the hematopoietic repopulating cell function and clonogenic potential but is not sufficient to initiate leukemia. Blood 2011; 117:4746-58. [PMID: 21389315 DOI: 10.1182/blood-2010-12-322230] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Infant acute lymphoblastic leukemia harboring the fusion mixed-lineage leukemia (MLL)-AF4 is associated with a dismal prognosis and very brief latency. Our limited understanding of transformation by MLL-AF4 is reflected in murine models, which do not accurately recapitulate the human disease. Human models for MLL-AF4 disease do not exist. Hematopoietic stem or progenitor cells (HSPCs) represent probable targets for transformation. Here, we explored in vitro and in vivo the impact of the enforced expression of MLL-AF4 in human cord blood-derived CD34(+) HSPCs. Intrabone marrow transplantation into NOD/SCID-IL2Rγ(-/-) mice revealed an enhanced multilineage hematopoietic engraftment, efficiency, and homing to other hematopoietic sites on enforced expression of MLL-AF4. Lentiviral transduction of MLL-AF4 into CD34(+) HSPCs increased the in vitro clonogenic potential of CD34(+) progenitors and promoted their proliferation. Consequently, cell cycle and apoptosis analyses suggest that MLL-AF4 conveys a selective proliferation coupled to a survival advantage, which correlates with changes in the expression of genes involved in apoptosis, sensing DNA damage and DNA repair. However, MLL-AF4 expression was insufficient to initiate leukemogenesis on its own, indicating that either additional hits (or reciprocal AF4-MLL product) may be required to initiate ALL or that cord blood-derived CD34(+) HSPCs are not the appropriate cellular target for MLL-AF4-mediated ALL.
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28
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The heterodimerization domains of MLL—FYRN and FYRC—are potential target structures in t(4;11) leukemia. Leukemia 2011; 25:663-70. [DOI: 10.1038/leu.2010.308] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
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29
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Stumpel DJPM, Schotte D, Lange-Turenhout EAM, Schneider P, Seslija L, de Menezes RX, Marquez VE, Pieters R, den Boer ML, Stam RW. Hypermethylation of specific microRNA genes in MLL-rearranged infant acute lymphoblastic leukemia: major matters at a micro scale. Leukemia 2010; 25:429-39. [PMID: 21116279 DOI: 10.1038/leu.2010.282] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
MLL-rearranged acute lymphoblastic leukemia (ALL) in infants (<1 year) is the most aggressive type of childhood leukemia. To develop more suitable treatment strategies, a firm understanding of the biology underlying this disease is of utmost importance. MLL-rearranged ALL displays a unique gene expression profile, partly explained by erroneous histone modifications. We recently showed that t(4;11)-positive infant ALL is also characterized by pronounced promoter CpG hypermethylation. In this study, we investigated whether this widespread hypermethylation also affected microRNA (miRNA) expression. We identified 11 miRNAs that were downregulated in t(4;11)-positive infant ALL as a consequence of CpG hypermethylation. Seven of these miRNAs were re-activated after exposure to the de-methylating agent Zebularine. Interestingly, five of these miRNAs are associated either with MLL or MLL fusions, and for miR-152 we found both MLL and DNA methyltransferase 1 (DNMT1) as potential targeted genes. Finally, a high degree of methylation of the miR-152 CpG island was strongly correlated with a poor clinical outcome. Our data suggests that inhibitors of methylation have a potential beyond re-expression of hypermethylated protein-coding genes in t(4;11)-positive infant ALL. In this study, we provide additional evidence that they should be tested for their efficacy in MLL-rearranged infant ALL in in vivo models.
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Affiliation(s)
- D J P M Stumpel
- Department of Pediatric Oncology/Hematology, Erasmus Medical Center, Sophia Children's Hospital, Rotterdam, The Netherlands
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30
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Kumar AR, Yao Q, Li Q, Sam TA, Kersey JH. t(4;11) leukemias display addiction to MLL-AF4 but not to AF4-MLL. Leuk Res 2010; 35:305-9. [PMID: 20869771 DOI: 10.1016/j.leukres.2010.08.011] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2010] [Revised: 08/17/2010] [Accepted: 08/19/2010] [Indexed: 01/19/2023]
Abstract
The most frequent MLL-gene rearrangement found in leukemia is a reciprocal translocation with AF4 on chromosome 4 resulting in the formation of the MLL-AF4 and the AF4-MLL fusion genes. The oncogenic role of MLL-AF4 is documented but the significance of the reciprocal product - AF4-MLL in leukemia is less clear. In the human leukemia cell lines - RS4;11 and SEMK2-M1, both of which express MLL-AF4 and AF4-MLL, we knocked down the expression of AF4-MLL using siRNA. Loss of AF4-MLL had no effect on the growth of either RS4;11 or SEMK2-M1 cells. Furthermore, in SEMK2-M1 cells there were no changes in cell cycle or apoptosis with loss of AF4-MLL. In contrast, knockdown of MLL-AF4 significantly inhibited growth of both RS4;11 and SEMK2-M1. Additionally, in SEMK2-M1 cells, loss of MLL-AF4 led to G2/M cell cycle arrest and increased apoptosis. Overall, these results demonstrate that in t(4;11) leukemia, the MLL-AF4 fusion protein is critical for leukemia cell proliferation and survival while the AF4-MLL fusion product is dispensable.
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Affiliation(s)
- Ashish R Kumar
- Masonic Cancer Center, University of Minnesota, Minneapolis, MN, USA.
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31
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The AF4·MLL fusion protein is capable of inducing ALL in mice without requirement of MLL·AF4. Blood 2010; 115:3570-9. [DOI: 10.1182/blood-2009-06-229542] [Citation(s) in RCA: 121] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Abstract
The chromosomal translocation t(4;11)(q21;q23) is the most frequent genetic aberration of the human MLL gene, resulting in high-risk acute lymphoblastic leukemia (ALL). To elucidate the leukemogenic potential of the fusion proteins MLL·AF4 and AF4·MLL, Lin−/Sca1+ purified cells (LSPCs) were retrovirally transduced with either both fusion genes or with MLL·AF4 or AF4·MLL alone. Recipients of AF4·MLL- or double-transduced LSPCs developed pro-B ALL, B/T biphenotypic acute leukemia, or mixed lineage leukemia. Transplantation of MLL·AF4- or mock-transduced LSPCs did not result in disease development during an observation period of 13 months. These findings indicate that the expression of the AF4·MLL fusion protein is capable of inducing acute lymphoblastic leukemia even in the absence of the MLL·AF4 fusion protein. In view of recent findings, these results may imply that t(4;11) leukemia is based on 2 oncoproteins, providing an explanation for the very early onset of disease in humans.
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32
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De Braekeleer E, Meyer C, Douet-Guilbert N, Morel F, Le Bris MJ, Berthou C, Arnaud B, Marschalek R, Férec C, De Braekeleer M. Complex and cryptic chromosomal rearrangements involving the MLL gene in acute leukemia: A study of 7 patients and review of the literature. Blood Cells Mol Dis 2010; 44:268-74. [DOI: 10.1016/j.bcmd.2010.02.011] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2010] [Accepted: 02/03/2010] [Indexed: 11/30/2022]
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33
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Trentin L, Giordan M, Dingermann T, Basso G, Te Kronnie G, Marschalek R. Two independent gene signatures in pediatric t(4;11) acute lymphoblastic leukemia patients. Eur J Haematol 2009; 83:406-19. [PMID: 19558506 DOI: 10.1111/j.1600-0609.2009.01305.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
OBJECTIVE Gene expression profiles become increasingly more important for diagnostic procedures, allowing clinical predictions including treatment response and outcome. However, the establishment of specific and robust gene signatures from microarray data sets requires the analysis of large numbers of patients and the application of complex biostatistical algorithms. Especially in case of rare diseases and due to these constrains, diagnostic centers with limited access to patients or bioinformatic resources are excluded from implementing these new technologies. METHOD In our study we sought to overcome these limitations and for proof of principle, we analyzed the rare t(4;11) leukemia disease entity. First, gene expression data of each t(4;11) leukemia patient were normalized by pairwise subtraction against normal bone marrow (n = 3) to identify significantly deregulated gene sets for each patient. RESULT A 'core signature' of 186 commonly deregulated genes present in each investigated t(4;11) leukemia patient was defined. Linking the obtained gene sets to four biological discriminators (HOXA gene expression, age at diagnosis, fusion gene transcripts and chromosomal breakpoints) divided patients into two distinct subgroups: the first one comprised infant patients with low HOXA genes expression and the MLL breakpoints within introns 11/12. The second one comprised non-infant patients with high HOXA expression and MLL breakpoints within introns 9/10. CONCLUSION A yet homogeneous leukemia entity was further subdivided, based on distinct genetic properties. This approach provided a simplified way to obtain robust and disease-specific gene signatures even in smaller cohorts.
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Affiliation(s)
- Luca Trentin
- Hemato-Oncology, Dept. of Pediatrics, University of Padova, Padova, Italy
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34
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Roberti MC, La Starza R, Surace C, Sirleto P, Pinto RM, Pierini V, Crescenzi B, Mecucci C, Angioni A. RABGAP1L gene rearrangement resulting from a der(Y)t(Y;1)(q12;q25) in acute myeloid leukemia arising in a child with Klinefelter syndrome. Virchows Arch 2009; 454:311-6. [PMID: 19184099 DOI: 10.1007/s00428-009-0732-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2008] [Revised: 01/02/2009] [Accepted: 01/08/2009] [Indexed: 11/28/2022]
Abstract
In this study, we report the molecular cytogenetic characterization of an acute myeloid leukemia with a der(Y)t(Y;1)(q12;q25) in bone marrow cells in a child with Klinefelter syndrome. Conventional cytogenetics demonstrated the unbalanced translocation, i.e., a trisomic 1q25-qter juxtaposed to Yq12 replaced the terminal segment of chromosome Y was acquired and present only on bone marrow cells. Fluorescence in situ hybridization showed that the breakpoint at 1q25 disrupted RABGAP1L, a strongly expressed gene in CFU-GEMM, erythroid cells, and megakaryocytes, while the Yq12 breakpoint fell within the heterochromatic region. As der(Y)t(Y;1)(q12;q25) was an isolated cytogenetic change, RABGAP1L rearrangement as well as gene(s) dosage effects correlated to 1q25-qter trisomy, and Yq12-qter loss may make a major contribution to leukemogenesis and/or disease progression.
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Affiliation(s)
- Maria Cristina Roberti
- Cytogenetics and Molecular Genetics, Bambino Gesù Children's Hospital, Piazza S. Onofrio 4, 00165, Rome, Italy
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35
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Clinical features and outcome of MLL gene rearranged acute lymphoblastic leukemia in infants with additional chromosomal abnormalities other than 11q23 translocation. Leuk Res 2008; 32:1523-9. [DOI: 10.1016/j.leukres.2008.03.018] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2008] [Revised: 03/03/2008] [Accepted: 03/19/2008] [Indexed: 11/23/2022]
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36
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Brandal P, Panagopoulos I, Bjerkehagen B, Gorunova L, Skjeldal S, Micci F, Heim S. Detection of a t(1;22)(q23;q12) translocation leading to an EWSR1-PBX1 fusion gene in a myoepithelioma. Genes Chromosomes Cancer 2008; 47:558-64. [PMID: 18383210 DOI: 10.1002/gcc.20559] [Citation(s) in RCA: 111] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Chromosome banding as well as molecular cytogenetic methods are of great help in the diagnosis of mesenchymal tumors. Myoepithelial neoplasms of soft tissue including myoepitheliomas, mixed tumors, and parachordomas are diagnoses that have been increasingly recognized the last few years. It is still debated which neoplasms should be included in these morphologically heterogeneous entities, and the boundaries between them are not clear-cut. The pathogenetic mechanisms behind myoepithelial tumors are unknown. Only five parachordomas and one mixed tumor have previously been karyotyped, and nothing is known about their molecular genetic characteristics. We present a mesenchymal tumor classified as a myoepithelioma that had a balanced translocation t(1;22)(q23;q12) as the sole karyotypic change. A novel EWSR1-PBX1 fusion gene consisting of exons 1-8 of the 5'-end of EWSR1 and exons 5-9 of the 3'-end of PBX1 was shown to result from the translocation. Both genes are known to be targeted also by other neoplasia-specific translocations, PBX1 in acute lymphoblastic leukemia and EWSR1 in several solid tumors, most of which are malignant. Based on the structure of the novel fusion gene detected, its transforming mechanism is thought to be the same as for other fusion genes involving EWSR1 or PBX1.
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Affiliation(s)
- Petter Brandal
- Department of Oncology, Division of Cancer Medicine and Radiotherapy, The Norwegian Radium Hospital, Rikshospitalet University Hospital, Montebello, Oslo, Norway.
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37
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Affiliation(s)
- Patrick A Zweidler-McKay
- The Children's Cancer Hospital at the University of Texas M.D. Anderson Cancer Center, Houston, Texas, USA
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