title: A genome-wide search for promoters that respond to increased MYCN reveals both new oncogenic and tumor suppressor microRNAs associated with aggressive neuroblastoma.
abstract: MYCN is a major driver of neuroblastoma tumorigenesis and MYCN amplification is the worst prognostic indicator of aggressive NB. To identify potentially therapeutic tumor suppressor microRNAs for aggressive NB, we utilized a conditional MYCN system to simulate MYCN-amplified and nonamplified tumor types and performed a genome-wide search for MYCN target microRNA promoters differentially repressed under high MYCN conditions. We identified 20 gene promoters hosting 30 microRNAs that were directly bound and differentially regulated by MYCN. Eleven of these genes showed significant clinical correlations for neuroblastoma with 4 genes linked with better survival and 7 genes linked with poor survival. Surprisingly, expression analysis of host genes and microRNAs demonstrated that 8 of 11 pairs were repressed by high levels of MYCN regardless of the clinical correlation of the host gene. We therefore predicted these intronic microRNAs would be tumor suppressors. In fact, detailed gain of function studies for two miRs, miR-591 and miR-558, confirmed potent tumor suppressive effects for miR-591 in orthotopic neuroblastoma xenografts. However, miR-558 markedly increased colony formation, proliferation, and tumor growth in vivo. Our data reveal host-gene independent functions of MYCN-target microRNAs and demonstrate that MYCN represses both tumor suppressive and proproliferative microRNAs.
authors.affiliation: Department of Pediatrics, Section of Hematology-Oncology, Baylor College of Medicine, Houston, Texas 77204, USA. jmshohet@texaschildrenshospital.org
authors.forename: Jason M
authors.initials: JM
authors.lastname: Shohet
authors.forename: Rajib
authors.initials: R
authors.lastname: Ghosh
authors.forename: Cristian
authors.initials: C
authors.lastname: Coarfa
authors.forename: Andrew
authors.initials: A
authors.lastname: Ludwig
authors.forename: Ashley L
authors.initials: AL
authors.lastname: Benham
authors.forename: Zaowen
authors.initials: Z
authors.lastname: Chen
authors.forename: Danielle M
authors.initials: DM
authors.lastname: Patterson
authors.forename: Eveline
authors.initials: E
authors.lastname: Barbieri
authors.forename: Pieter
authors.initials: P
authors.lastname: Mestdagh
authors.forename: Denae N
authors.initials: DN
authors.lastname: Sikorski
authors.forename: Aleksandar
authors.initials: A
authors.lastname: Milosavljevic
authors.forename: Eugene S
authors.initials: ES
authors.lastname: Kim
authors.forename: Preethi H
authors.initials: PH
authors.lastname: Gunaratne
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D047369:Chromatin Immunoprecipitation / Q000379:methods; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D053263:Gene Regulatory Networks; D016147:Genes, Tumor Suppressor; D055106:Genome-Wide Association Study; D006801:Humans; D051379:Mice; D008819:Mice, Nude; D035683:MicroRNAs / Q000096:biosynthesis / Q000235:genetics*; D000071447:N-Myc Proto-Oncogene Protein; D009447:Neuroblastoma / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D009687:Nuclear Proteins / Q000096:biosynthesis / Q000235:genetics*; D015513:Oncogene Proteins / Q000096:biosynthesis / Q000235:genetics*; D011379:Prognosis; D011401:Promoter Regions, Genetic; D014183:Transplantation, Heterologous; D014407:Tumor Cells, Cultured
chemical_list: C459801:MYCN protein, human; D035683:MicroRNAs; D000071447:N-Myc Proto-Oncogene Protein; D009687:Nuclear Proteins; D015513:Oncogene Proteins