title: DAX-1 Expression in Pediatric Rhabdomyosarcomas: Another Immunohistochemical Marker Useful in the Diagnosis of Translocation Positive Alveolar Rhabdomyosarcoma.
abstract: OBJECTIVE
  The aim of this study was to investigate the expression of DAX-1 in a series of pediatric rhabdomyosarcomas (RMS) with known translocation and compare it to Ap2β, known to be selectively expressed in ARMS.
  
  
  METHODS
  We revised a series of 71 alveolar rhabdomyosarcomas (ARMS), enrolled in the Italian Protocols RMS 79 and 96, and 23 embryonal rhabdomyosarcomas (ERMS) as controls. Before investigating Ap2β and DAX-1, ARMS were reviewed and reclassified as 48 ARMS and 23 non-ARMS.
  
  
  RESULTS
  Translocation positive ARMS showed a characteristic Ap2β/DAX-1+ staining pattern in 78% of cases, while 76% of classic ERMS were negative for both. Ap2β alone was positive in 3.9% of RMS lacking translocation, whereas DAX-1 alone was positive in 25.4%. Conversely, 9% and 6% of translocation positive ARMS were positive only for DAX-1 or Ap2β, respectively. The 23 non-ARMS shared the same phenotype as ERMS but had a higher frequency of DAX-1 expression.
  
  
  CONCLUSIONS
  DAX-1 is less specific than Ap2β, however it is a sensitive marker for translocation positive ARMS and can be helpful in their diagnosis if used in combination with Ap2β.
authors.affiliation: Pediatric Surgery, Department of Women's and Children's Health, University-Hospital of Padua, Padua, Italy.
authors.forename: Calogero
authors.initials: C
authors.lastname: Virgone
authors.affiliation: Institut de Pharmacologie Moléculaire et Cellulaire, Unité Mixte de Recherche 7275, CNRS, Valbonne, France; Université de Nice-Sophia Antipolis, Valbonne, France.
authors.forename: Enzo
authors.initials: E
authors.lastname: Lalli
authors.affiliation: Hematology Oncology, Department of Women's and Children's Health, University-Hospital of Padua, Padua, Italy.
authors.forename: Gianni
authors.initials: G
authors.lastname: Bisogno
authors.affiliation: Pathology Unit, San Bortolo Hospital, Vicenza, Italy.
authors.forename: Elena
authors.initials: E
authors.lastname: Lazzari
authors.affiliation: Laboratory of Translational Research in Pediatric Cancer, Vall d'Hebron Research Institute, Universitat Autònoma de Barcelona, Barcelona, Spain.
authors.forename: Josep
authors.initials: J
authors.lastname: Roma
authors.affiliation: Istituto della Ricerca Pediatrica "Città della Speranza", Laboratorio di Biologia dei Tumori Solidi, Padova, Italy.
authors.forename: Angelica
authors.initials: A
authors.lastname: Zin
authors.affiliation: Istituto della Ricerca Pediatrica "Città della Speranza", Laboratorio di Biologia dei Tumori Solidi, Padova, Italy.
authors.forename: Elena
authors.initials: E
authors.lastname: Poli
authors.affiliation: Pediatric Surgery, Department of Women's and Children's Health, University-Hospital of Padua, Padua, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Cecchetto
authors.affiliation: Pediatric Surgery, Department of Women's and Children's Health, University-Hospital of Padua, Padua, Italy.
authors.forename: Patrizia
authors.initials: P
authors.lastname: Dall'Igna
authors.affiliation: Pathology Unit, Department of Medical and Diagnostic Sciences and Special Therapies, University of Padua, Padua, Italy.
authors.forename: Rita
authors.initials: R
authors.lastname: Alaggio
mesh_terms: D000293:Adolescent; D000328:Adult; D014408:Biomarkers, Tumor / Q000378:metabolism*; D002648:Child; D002675:Child, Preschool; D057137:DAX-1 Orphan Nuclear Receptor / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D012208:Rhabdomyosarcoma / Q000175:diagnosis / Q000378:metabolism*; D014178:Translocation, Genetic; D055815:Young Adult
chemical_list: D014408:Biomarkers, Tumor; D057137:DAX-1 Orphan Nuclear Receptor; C539965:NR0B1 protein, human