title: Apurinic/apyrimidinic endonuclease expression in pediatric yolk sac tumors.
abstract: BACKGROUND
  The enzyme apurinic/apyriminidic endonuclease/redox factor 1 (Ape1/ref1), a key protein in the base excision repair pathway, displays repair and redox activity. We examined the role of Ape1/ref1 and a protein it regulates, hypoxia inducible factor 1 alpha (HIF-1 alpha) in pediatric yolk sac tumors.
  
  
  METHODS
  Using an immunohistochemical evaluation, 16 pediatric yolk sac tumors were evaluated for Ape1/ref1 and HIF-1 alpha expression. Samples were obtained from archival tissue.
  
  
  RESULTS
  We demonstrated high levels of expression of Ape1/ref1 in 14/16 of the tumors. This expression was limited to the nucleus of the viable portion of each tumor. High levels of HIF-1 alpha expression was noted in half of the same tumors and localized to both the nucleus and cytoplasm of the viable tumor.
  
  
  CONCLUSIONS
  The high levels of expression of Ape1/ref1 in this group of chemosensitive tumors may be related to the subcellular location or redox regulatory activity of one of the other factors controlled by Ape1/ref1.
authors.affiliation: Indiana University School of Medicine, Department of Pediatric Hematology/Oncology, Indianapolis, IN, USA. bthomson@iupui.edu
authors.forename: B G
authors.initials: BG
authors.lastname: Thomson
authors.forename: R
authors.initials: R
authors.lastname: Tritt
authors.forename: M
authors.initials: M
authors.lastname: Davis
authors.forename: E J
authors.initials: EJ
authors.lastname: Perlman
authors.forename: M R
authors.initials: MR
authors.lastname: Kelley
mesh_terms: D019757:Carbon-Oxygen Lyases / Q000032:analysis*; D002675:Child, Preschool; D043603:DNA-(Apurinic or Apyrimidinic Site) Lyase; D004268:DNA-Binding Proteins / Q000032:analysis; D018240:Endodermal Sinus Tumor / Q000201:enzymology*; D005260:Female; D006801:Humans; D051793:Hypoxia-Inducible Factor 1; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D009363:Neoplasm Proteins / Q000032:analysis*; D009687:Nuclear Proteins / Q000032:analysis; D014157:Transcription Factors / Q000032:analysis
chemical_list: D004268:DNA-Binding Proteins; C497442:HIF1A protein, human; D051793:Hypoxia-Inducible Factor 1; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D009363:Neoplasm Proteins; D009687:Nuclear Proteins; D014157:Transcription Factors; D019757:Carbon-Oxygen Lyases; C085108:APEX1 protein, human; D043603:DNA-(Apurinic or Apyrimidinic Site) Lyase