title: GD2 synthase: a new molecular marker for detecting neuroblastoma.
abstract: BACKGROUND
  Neuroblastomas (NBs) almost ubiquitously express the ganglioside GD2. GD2 synthesis is dependent on the key enzyme GD2 synthase. Thus, GD2 synthase transcript may prove to be a potential molecular marker of NB.
  
  
  METHODS
  Seventy-seven NB tumor tissues of all stages, 5 NB cell lines, and 26 normal bone marrows (BMs) and peripheral blood (PBL) samples, as well as 26 non-NB remission-BMs were analyzed for the expression of GD2 synthase by a highly sensitive reverse transcriptase-polymerase chain reaction (RT-PCR) and chemiluminescence detection. One hundred fifty-two NB BMs were tested and comparisons were made among three independent detection techniques, namely GD2 synthase RT-PCR, immunofluorescence (IF), and histology (HIST).
  
  
  RESULTS
  GD2 synthase transcript was present in 5 of 5 cell lines and in 77 of 77 tumors tested. Among 116 marrows that were positive by at least 1 of the 3 methods, 78% were detectable by GD2 synthase, 68% by IF, and 46% by HIST. Seventy-six percent of positive BMs that were obtained during treatment and follow-up had GD2 synthase expression, whereas only 29% were HIST positive. Correlation between RT-PCR and IF was high (P = 0.001), and positivity by 3 out of 3 methods was strongly correlated with poor survival (P < 0.01). Of note, marrows tested at the time of chemotherapy were positive by at least 2 out of 3 methods and were associated with adverse outcome (P = 0.01). Serial samples (n = 28) in 5 patients demonstrated close agreement between RT-PCR and patient disease status.
  
  
  CONCLUSIONS
  The current study found that molecular detection of GD2 synthase transcript in NB BMs may have potential value in detecting rare tumor cells.
authors.affiliation: Department of Pediatrics, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10021, USA.
authors.forename: M S
authors.initials: MS
authors.lastname: Lo Piccolo
authors.forename: N K
authors.initials: NK
authors.lastname: Cheung
authors.forename: I Y
authors.initials: IY
authors.lastname: Cheung
mesh_terms: D014408:Biomarkers, Tumor / Q000378:metabolism*; D001853:Bone Marrow / Q000201:enzymology; D005455:Fluorescent Antibody Technique; D006801:Humans; D008163:Luminescent Measurements; D017350:N-Acetylgalactosaminyltransferases / Q000235:genetics / Q000378:metabolism*; D009367:Neoplasm Staging; D009447:Neuroblastoma / Q000175:diagnosis / Q000201:enzymology* / Q000473:pathology; D012313:RNA / Q000032:analysis; D012189:Retrospective Studies; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016019:Survival Analysis; D014407:Tumor Cells, Cultured
chemical_list: D014408:Biomarkers, Tumor; D012313:RNA; D017350:N-Acetylgalactosaminyltransferases; C023220:(N-acetylneuraminyl)-galactosylglucosylceramide N-acetylgalactosaminyltransferase