title: miR-10a overexpression is associated with NPM1 mutations and MDM4 downregulation in intermediate-risk acute myeloid leukemia.
abstract: OBJECTIVE
  The study investigated differential microRNA (miRNA) expression patterns in acute myeloid leukemia (AML) patients with intermediate-risk (IR) characteristics. After characterization and validation of miR-10a, which was specifically upregulated in nucleophosmin 1 (NPM1) mutant AML samples, functional consequences of miR-10a overexpression were further delineated in vitro.
  
  
  METHODS
  Microarray analysis of miRNAs in bone marrow samples from AML (IR) patients with NPM1 mutations and healthy donors was performed to detect differential expression patterns. After validation of miRNA expression specific for NPM1 mutation in AML patients by quantitative reverse transcription polymerase chain reaction, a functional target gene search was conducted using complementary DNA microarray data from samples transfected with miR-10a. Potential target gene validation was done using transient transfection of K562 cells followed by Western blotting and luciferase reporter assay.
  
  
  RESULTS
  In comparison with wild-type samples, NPM1 mutant AML samples were shown to markedly overexpress miR-10a. Subsequent in vitro miR-10a overexpression induced differential gene expression as determined by microarray analysis. Here the murine double minute 4 (MDM4) gene turned out as a candidate gene for miR-10a. Validation of MDM4 in leukemic cells revealed a robust negative relationship between miR-10a overexpression and MDM4 downregulation. Furthermore, we determined an inverse association between miR-10a and MDM4 expression in AML (IR) samples with respect to their NPM1 mutational status.
  
  
  CONCLUSIONS
  miR-10a expression is highly characteristic for AML (IR) patients with NPM1 mutations and may influence its biological properties in AML by interfering with the p53 machinery partly regulated by MDM4.
authors.affiliation: Asuragen Inc., Austin, Tx., USA.
authors.forename: Dmitriy
authors.initials: D
authors.lastname: Ovcharenko
authors.forename: Friedrich
authors.initials: F
authors.lastname: Stölzel
authors.forename: David
authors.initials: D
authors.lastname: Poitz
authors.forename: Fernando
authors.initials: F
authors.lastname: Fierro
authors.forename: Markus
authors.initials: M
authors.lastname: Schaich
authors.forename: Andreas
authors.initials: A
authors.lastname: Neubauer
authors.forename: Kevin
authors.initials: K
authors.lastname: Kelnar
authors.forename: Timothy
authors.initials: T
authors.lastname: Davison
authors.forename: Carsten
authors.initials: C
authors.lastname: Müller-Tidow
authors.forename: Christian
authors.initials: C
authors.lastname: Thiede
authors.forename: Martin
authors.initials: M
authors.lastname: Bornhäuser
authors.forename: Gerhard
authors.initials: G
authors.lastname: Ehninger
authors.forename: David
authors.initials: D
authors.lastname: Brown
authors.forename: Thomas
authors.initials: T
authors.lastname: Illmer
mesh_terms: D020413:3' Untranslated Regions; D000208:Acute Disease; D000368:Aged; D001853:Bone Marrow / Q000378:metabolism; D018797:Cell Cycle Proteins; D045744:Cell Line, Tumor / Q000378:metabolism; D019008:Drug Resistance, Neoplasm / Q000235:genetics; D005260:Female; D015973:Gene Expression Regulation, Leukemic / Q000235:genetics*; D006801:Humans; D007951:Leukemia, Myeloid / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D008297:Male; D035683:MicroRNAs / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D008875:Middle Aged; D009154:Mutation; D009363:Neoplasm Proteins / Q000096:biosynthesis / Q000235:genetics*; D009687:Nuclear Proteins / Q000096:biosynthesis / Q000235:genetics*; D000090243:Nucleophosmin; D020411:Oligonucleotide Array Sequence Analysis; D011518:Proto-Oncogene Proteins / Q000096:biosynthesis / Q000235:genetics*; D012334:RNA, Neoplasm / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D012306:Risk; D014162:Transfection; D014407:Tumor Cells, Cultured / Q000378:metabolism; D016159:Tumor Suppressor Protein p53 / Q000502:physiology
chemical_list: D020413:3' Untranslated Regions; D018797:Cell Cycle Proteins; C482775:MDM4 protein, human; C547183:MIRN10 microRNA, human; D035683:MicroRNAs; C000716967:NPM1 protein, human; D009363:Neoplasm Proteins; D009687:Nuclear Proteins; D011518:Proto-Oncogene Proteins; D012334:RNA, Neoplasm; C495901:TP53 protein, human; D016159:Tumor Suppressor Protein p53; D000090243:Nucleophosmin