Hélène Jakobczyk1, Lydie Debaize1, Benoit Soubise2, Stéphane Avner1, Jérémie Rouger-Gaudichon1,3, Séverine Commet2,4, Yan Jiang2,5, Aurélien A Sérandour6, Anne-Gaëlle Rio1, Jason S Carroll7, Christian Wichmann8, Michael Lie-A-Ling9, Georges Lacaud9, Laurent Corcos2, Gilles Salbert1, Marie-Dominique Galibert1,10, Virginie Gandemer1,11, Marie-Bérengère Troadec12,13,14. 1. Univ Rennes 1, CNRS, IGDR (Institut de génétique et développement de Rennes) - UMR 6290, 35000, Rennes, France. 2. Univ Brest, Inserm, EFS, UMR 1078, GGB, 29200, Brest, France. 3. Département d'onco-hematologie pediatrique, Centre Hospitalier Universitaire de Caen Normandie, Caen, France. 4. CHRU Brest, Service de génétique, laboratoire de génétique chromosomique, 22 avenue Camille Desmoulins, 29238, Brest Cedex 3, France. 5. Department of Hematology, The First Hospital of Jilin University, Changchun, China. 6. Université de Nantes, Ecole Centrale de Nantes, Inserm, CRCINA, Nantes, France. 7. Cancer Research UK Cambridge Institute, University of Cambridge, Cambridge, CB2 0RE, UK. 8. Department of Transfusion Medicine, Cell Therapeutics and Haemostasis, Ludwig-Maximilians-University of Munich, Munich, Germany. 9. Cancer Research UK Manchester Institute, University of Manchester, Aderley Park, Macclesfield, SK10 4TG, UK. 10. Service de Génétique et Génomique Moléculaire, Centre Hospitalier Universitaire de Rennes (CHU-Rennes), 35033, Rennes, France. 11. Department of Pediatric Hemato-Oncology, Centre Hospitalier Universitaire de Rennes (CHU-Rennes), 35203, Rennes, France. 12. Univ Rennes 1, CNRS, IGDR (Institut de génétique et développement de Rennes) - UMR 6290, 35000, Rennes, France. marie-berengere.troadec@univ-brest.fr. 13. Univ Brest, Inserm, EFS, UMR 1078, GGB, 29200, Brest, France. marie-berengere.troadec@univ-brest.fr. 14. CHRU Brest, Service de génétique, laboratoire de génétique chromosomique, 22 avenue Camille Desmoulins, 29238, Brest Cedex 3, France. marie-berengere.troadec@univ-brest.fr.
Abstract
BACKGROUND: B Cell Precursor Acute Lymphoblastic Leukemia (BCP-ALL) is the most common pediatric cancer. Identifying key players involved in proliferation of BCP-ALL cells is crucial to propose new therapeutic targets. Runt Related Transcription Factor 1 (RUNX1) and Core-Binding Factor Runt Domain Alpha Subunit 2 Translocated To 3 (CBFA2T3, ETO2, MTG16) are master regulators of hematopoiesis and are implicated in leukemia. METHODS: We worked with BCP-ALL mononuclear bone marrow patients' cells and BCP-ALL cell lines, and performed Chromatin Immunoprecipitations followed by Sequencing (ChIP-Seq), co-immunoprecipitations (co-IP), proximity ligation assays (PLA), luciferase reporter assays and mouse xenograft models. RESULTS: We demonstrated that CBFA2T3 transcript levels correlate with RUNX1 expression in the pediatric t(12;21) ETV6-RUNX1 BCP-ALL. By ChIP-Seq in BCP-ALL patients' cells and cell lines, we found that RUNX1 is recruited on its promoter and on an enhancer of CBFA2T3 located - 2 kb upstream CBFA2T3 promoter and that, subsequently, the transcription factor RUNX1 drives both RUNX1 and CBFA2T3 expression. We demonstrated that, mechanistically, RUNX1 and CBFA2T3 can be part of the same complex allowing CBFA2T3 to strongly potentiate the activity of the transcription factor RUNX1. Finally, we characterized a CBFA2T3-mimicking peptide that inhibits the interaction between RUNX1 and CBFA2T3, abrogating the activity of this transcription complex and reducing BCP-ALL lymphoblast proliferation. CONCLUSIONS: Altogether, our findings reveal a novel and important activation loop between the transcription regulator CBFA2T3 and the transcription factor RUNX1 that promotes BCP-ALL proliferation, supporting the development of an innovative therapeutic approach based on the NHR2 subdomain of CBFA2T3 protein.
BACKGROUND: B Cell Precursor Acute Lymphoblastic Leukemia (BCP-ALL) is the most common pediatric cancer. Identifying key players involved in proliferation of BCP-ALL cells is crucial to propose new therapeutic targets. Runt Related Transcription Factor 1 (RUNX1) and Core-Binding Factor Runt Domain Alpha Subunit 2 Translocated To 3 (CBFA2T3, ETO2, MTG16) are master regulators of hematopoiesis and are implicated in leukemia. METHODS: We worked with BCP-ALL mononuclear bone marrow patients' cells and BCP-ALL cell lines, and performed Chromatin Immunoprecipitations followed by Sequencing (ChIP-Seq), co-immunoprecipitations (co-IP), proximity ligation assays (PLA), luciferase reporter assays and mouse xenograft models. RESULTS: We demonstrated that CBFA2T3 transcript levels correlate with RUNX1 expression in the pediatric t(12;21) ETV6-RUNX1BCP-ALL. By ChIP-Seq in BCP-ALL patients' cells and cell lines, we found that RUNX1 is recruited on its promoter and on an enhancer of CBFA2T3 located - 2 kb upstream CBFA2T3 promoter and that, subsequently, the transcription factor RUNX1 drives both RUNX1 and CBFA2T3 expression. We demonstrated that, mechanistically, RUNX1 and CBFA2T3 can be part of the same complex allowing CBFA2T3 to strongly potentiate the activity of the transcription factor RUNX1. Finally, we characterized a CBFA2T3-mimicking peptide that inhibits the interaction between RUNX1 and CBFA2T3, abrogating the activity of this transcription complex and reducing BCP-ALL lymphoblast proliferation. CONCLUSIONS: Altogether, our findings reveal a novel and important activation loop between the transcription regulator CBFA2T3 and the transcription factor RUNX1 that promotes BCP-ALL proliferation, supporting the development of an innovative therapeutic approach based on the NHR2 subdomain of CBFA2T3 protein.