title: Mutation in TET2 in myeloid cancers.
abstract: BACKGROUND
  The myelodysplastic syndromes and myeloproliferative disorders are associated with deregulated production of myeloid cells. The mechanisms underlying these disorders are not well defined.
  
  
  METHODS
  We conducted a combination of molecular, cytogenetic, comparative-genomic-hybridization, and single-nucleotide-polymorphism analyses to identify a candidate tumor-suppressor gene common to patients with myelodysplastic syndromes, myeloproliferative disorders, and acute myeloid leukemia (AML). The coding sequence of this gene, TET2, was determined in 320 patients. We analyzed the consequences of deletions or mutations in TET2 with the use of in vitro clonal assays and transplantation of human tumor cells into mice.
  
  
  RESULTS
  We initially identified deletions or mutations in TET2 in three patients with myelodysplastic syndromes, in three of five patients with myeloproliferative disorders, in two patients with primary AML, and in one patient with secondary AML. We selected the six patients with myelodysplastic syndromes or AML because they carried acquired rearrangements on chromosome 4q24; we selected the five patients with myeloproliferative disorders because they carried a dominant clone in hematopoietic progenitor cells that was positive for the V617F mutation in the Janus kinase 2 (JAK2) gene. TET2 defects were observed in 15 of 81 patients with myelodysplastic syndromes (19%), in 24 of 198 patients with myeloproliferative disorders (12%) (with or without the JAK2 V617F mutation), in 5 of 21 patients with secondary AML (24%), and in 2 of 9 patients with chronic myelomonocytic leukemia (22%). TET2 defects were present in hematopoietic stem cells and preceded the JAK2 V617F mutation in the five samples from patients with myeloproliferative disorders that we analyzed.
  
  
  CONCLUSIONS
  Somatic mutations in TET2 occur in about 15% of patients with various myeloid cancers.
authors.affiliation: INSERM U790, Institut Gustave Roussy, Villejuif, France.
authors.forename: François
authors.initials: F
authors.lastname: Delhommeau
authors.forename: Sabrina
authors.initials: S
authors.lastname: Dupont
authors.forename: Véronique
authors.initials: V
authors.lastname: Della Valle
authors.forename: Chloé
authors.initials: C
authors.lastname: James
authors.forename: Severine
authors.initials: S
authors.lastname: Trannoy
authors.forename: Aline
authors.initials: A
authors.lastname: Massé
authors.forename: Olivier
authors.initials: O
authors.lastname: Kosmider
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Le Couedic
authors.forename: Fabienne
authors.initials: F
authors.lastname: Robert
authors.forename: Antonio
authors.initials: A
authors.lastname: Alberdi
authors.forename: Yann
authors.initials: Y
authors.lastname: Lécluse
authors.forename: Isabelle
authors.initials: I
authors.lastname: Plo
authors.forename: François J
authors.initials: FJ
authors.lastname: Dreyfus
authors.forename: Christophe
authors.initials: C
authors.lastname: Marzac
authors.forename: Nicole
authors.initials: N
authors.lastname: Casadevall
authors.forename: Catherine
authors.initials: C
authors.lastname: Lacombe
authors.forename: Serge P
authors.initials: SP
authors.lastname: Romana
authors.forename: Philippe
authors.initials: P
authors.lastname: Dessen
authors.forename: Jean
authors.initials: J
authors.lastname: Soulier
authors.forename: Franck
authors.initials: F
authors.lastname: Viguié
authors.forename: Michaela
authors.initials: M
authors.lastname: Fontenay
authors.forename: William
authors.initials: W
authors.lastname: Vainchenker
authors.forename: Olivier A
authors.initials: OA
authors.lastname: Bernard
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D018952:Antigens, CD34; D002894:Chromosomes, Human, Pair 4 / Q000235:genetics; D055028:Comparative Genomic Hybridization; D004268:DNA-Binding Proteins / Q000235:genetics*; D049308:Dioxygenases; D015321:Gene Rearrangement; D006412:Hematopoietic Stem Cells / Q000276:immunology; D006801:Humans; D053614:Janus Kinase 2 / Q000235:genetics; D015470:Leukemia, Myeloid, Acute / Q000235:genetics*; D051379:Mice; D016688:Mice, Inbred NOD; D016513:Mice, SCID; D008969:Molecular Sequence Data; D009154:Mutation; D009190:Myelodysplastic Syndromes / Q000235:genetics*; D009196:Myeloproliferative Disorders / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D017384:Sequence Deletion
chemical_list: D018952:Antigens, CD34; D004268:DNA-Binding Proteins; D011518:Proto-Oncogene Proteins; D049308:Dioxygenases; C541081:TET2 protein, human; C507924:JAK2 protein, human; D053614:Janus Kinase 2