title: Targeting MYCN-Driven Transcription By BET-Bromodomain Inhibition.
abstract: Targeting BET proteins was previously shown to have specific antitumoral efficacy against MYCN-amplified neuroblastoma. We here assess the therapeutic efficacy of the BET inhibitor, OTX015, in preclinical neuroblastoma models and extend the knowledge on the role of BRD4 in MYCN-driven neuroblastoma.
  
  
  
  The efficacy of OTX015 was assessed in in vitro and in vivo models of human and murine MYCN-driven neuroblastoma. To study the effects of BET inhibition in the context of high MYCN levels, MYCN was ectopically expressed in human and murine cells. The effect of OTX015 on BRD4-regulated transcriptional pause release was analyzed using BRD4 and H3K27Ac chromatin immunoprecipitation coupled with DNA sequencing (ChIP-Seq) and gene expression analysis in neuroblastoma cells treated with OTX015 compared with vehicle control.
  
  
  
  OTX015 showed therapeutic efficacy against preclinical MYCN-driven neuroblastoma models. Similar to previously described BET inhibitors, concurrent MYCN repression was observed in OTX015-treated samples. Ectopic MYCN expression, however, did not abrogate effects of OTX015, indicating that MYCN repression is not the only target of BET proteins in neuroblastoma. When MYCN was ectopically expressed, BET inhibition still disrupted MYCN target gene transcription without affecting MYCN expression. We found that BRD4 binds to super-enhancers and MYCN target genes, and that OTX015 specifically disrupts BRD4 binding and transcription of these genes.
  
  
  
  We show that OTX015 is effective against mouse and human MYCN-driven tumor models and that BRD4 not only targets MYCN, but specifically occupies MYCN target gene enhancers as well as other genes associated with super-enhancers. Clin Cancer Res; 22(10); 2470-81. ©2015 AACR.
authors.affiliation: Molecular Pharmacology & Chemistry Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, New York. Department of Pediatric Oncology and Hematology, University Children's Hospital Essen, Essen, Germany. henssena@mskcc.org.
authors.forename: Anton
authors.initials: A
authors.lastname: Henssen
authors.affiliation: Department of Pediatric Oncology and Hematology, University Children's Hospital Essen, Essen, Germany. German Consortium for Translational Cancer Research (DKTK), Partner Site Essen/Duesseldorf, Essen, Germany.
authors.forename: Kristina
authors.initials: K
authors.lastname: Althoff
authors.affiliation: Department of Pediatric Oncology and Hematology, University Children's Hospital Essen, Essen, Germany.
authors.forename: Andrea
authors.initials: A
authors.lastname: Odersky
authors.affiliation: Center of Medical Genetics Ghent (CMGG), Ghent University Hospital, Ghent, Belgium.
authors.forename: Anneleen
authors.initials: A
authors.lastname: Beckers
authors.affiliation: Human Oncology and Pathogenesis Program, Memorial Sloan Kettering Cancer Center, New York, New York.
authors.forename: Richard
authors.initials: R
authors.lastname: Koche
authors.affiliation: Center of Medical Genetics Ghent (CMGG), Ghent University Hospital, Ghent, Belgium.
authors.forename: Frank
authors.initials: F
authors.lastname: Speleman
authors.affiliation: Department of Pediatric Oncology and Hematology, University Children's Hospital Essen, Essen, Germany. German Consortium for Translational Cancer Research (DKTK), Partner Site Essen/Duesseldorf, Essen, Germany.
authors.forename: Simon
authors.initials: S
authors.lastname: Schäfers
authors.affiliation: Neuroblastoma Genomics, B087, German Cancer Research Center (DKFZ), Heidelberg, Germany.
authors.forename: Emma
authors.initials: E
authors.lastname: Bell
authors.affiliation: Neuroblastoma Genomics, B087, German Cancer Research Center (DKFZ), Heidelberg, Germany.
authors.forename: Maike
authors.initials: M
authors.lastname: Nortmeyer
authors.affiliation: Neuroblastoma Genomics, B087, German Cancer Research Center (DKFZ), Heidelberg, Germany.
authors.forename: Frank
authors.initials: F
authors.lastname: Westermann
authors.affiliation: Center of Medical Genetics Ghent (CMGG), Ghent University Hospital, Ghent, Belgium.
authors.forename: Katleen
authors.initials: K
authors.lastname: De Preter
authors.affiliation: Institute of Pathology, University Hospital Cologne, Cologne, Germany.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Florin
authors.affiliation: New Oncology, Köln, Germany. Institut für Hämatopathologie Hamburg, Hamburg, Germany.
authors.forename: Lukas
authors.initials: L
authors.lastname: Heukamp
authors.affiliation: Department of Pediatric Oncology and Hematology, University Children's Hospital Essen, Essen, Germany.
authors.forename: Annika
authors.initials: A
authors.lastname: Spruessel
authors.affiliation: Department of Pediatric Oncology/Hematology, Charité-Universitätsmedizin Berlin, Berlin, Germany.
authors.forename: Kathy
authors.initials: K
authors.lastname: Astrahanseff
authors.affiliation: Department of Pediatric Oncology and Hematology, University Children's Hospital Essen, Essen, Germany.
authors.forename: Sven
authors.initials: S
authors.lastname: Lindner
authors.affiliation: Department of Pediatric Oncology and Hematology, University Children's Hospital Essen, Essen, Germany.
authors.forename: Natalie
authors.initials: N
authors.lastname: Sadowski
authors.affiliation: Department of Pediatric Oncology and Hematology, University Children's Hospital Essen, Essen, Germany.
authors.forename: Alexander
authors.initials: A
authors.lastname: Schramm
authors.affiliation: Oncology Therapeutic Development, Clichy, France.
authors.forename: Lucile
authors.initials: L
authors.lastname: Astorgues-Xerri
authors.affiliation: Oncology Therapeutic Development, Clichy, France.
authors.forename: Maria E
authors.initials: ME
authors.lastname: Riveiro
authors.affiliation: Department of Pediatric Oncology/Hematology, Charité-Universitätsmedizin Berlin, Berlin, Germany.
authors.forename: Angelika
authors.initials: A
authors.lastname: Eggert
authors.affiliation: Oncology Therapeutic Development, Clichy, France. Oncoethix, Lausanne, Switzerland.
authors.forename: Esteban
authors.initials: E
authors.lastname: Cvitkovic
authors.affiliation: Department of Pediatric Oncology and Hematology, University Children's Hospital Essen, Essen, Germany. German Consortium for Translational Cancer Research (DKTK), Partner Site Essen/Duesseldorf, Essen, Germany. Neuroblastoma Genomics, B087, German Cancer Research Center (DKFZ), Heidelberg, Germany. Translational Neuro-Oncology, West German Cancer Center (WTZ), University Hospital Essen, University Duisburg-Essen, Essen, Germany. Centre for Medical Biotechnology, University Duisburg-Essen, Essen, Germany.
authors.forename: Johannes H
authors.initials: JH
authors.lastname: Schulte
mesh_terms: D000083:Acetanilides / Q000494:pharmacology; D000818:Animals; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D002460:Cell Line; D045744:Cell Line, Tumor; D005260:Female; D015870:Gene Expression / Q000187:drug effects; D006575:Heterocyclic Compounds, 3-Ring / Q000494:pharmacology; D006801:Humans; D051379:Mice; D008819:Mice, Nude; D000071447:N-Myc Proto-Oncogene Protein / Q000378:metabolism*; D009419:Nerve Tissue Proteins / Q000037:antagonists & inhibitors* / Q000378:metabolism; D009447:Neuroblastoma / Q000188:drug therapy / Q000378:metabolism; D009687:Nuclear Proteins / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism; D014158:Transcription, Genetic / Q000187:drug effects*
chemical_list: D000083:Acetanilides; D000970:Antineoplastic Agents; D006575:Heterocyclic Compounds, 3-Ring; D000071447:N-Myc Proto-Oncogene Protein; D009419:Nerve Tissue Proteins; D009687:Nuclear Proteins; C000605331:OTX015; D014157:Transcription Factors