title: Different subcellular localization of ALCAM molecules in neuroblastoma: Association with relapse.
abstract: BACKGROUND
  The Activated Leukocyte Cell Adhesion Molecule (ALCAM/CD166), involved in nervous system development, has been linked to tumor progression and metastasis in several tumors. No information is available on ALCAM expression in neuroblastoma, a childhood neoplasia originating from the sympathetic nervous system.
  
  
  METHODS
  ALCAM expression was analysed by immunofluorescence and immunohistochemistry on differentiated neuroblastoma cell lines and on archival specimens of stroma-poor, not MYCN amplified, resectable neuroblastoma tumors, respectively.
  
  
  RESULTS
  ALCAM is variously expressed in neuroblastoma cell lines, is shed by metalloproteases and is cleaved by ADAM17/TACE in vitro. ALCAM is expressed in neuroblastoma primary tumors with diverse patterns of subcellular localization and is highly expressed in the neuropil area in a subgroup of cases. Tumor specimens showing high expression of ALCAM at the membrane of the neuroblast body or low levels in the neuropil area are associated with relapse (P=0.044 and P<0.0001, respectively). In vitro differentiated neuroblastoma cells show strong ALCAM expression on neurites, suggesting that ALCAM expression in the neuropil is related to a differentiated phenotype.
  
  
  CONCLUSIONS
  Assessment of ALCAM localization by immunohistochemistry may help to identify patients who, in the absence of negative prognostic factors, are at risk of relapse and require a more careful follow-up.
authors.affiliation: Laboratory of Oncology, Gaslini Institute, Genoa, Italy.
authors.forename: Maria Valeria
authors.initials: MV
authors.lastname: Corrias
authors.forename: Claudio
authors.initials: C
authors.lastname: Gambini
authors.forename: Andrea
authors.initials: A
authors.lastname: Gregorio
authors.forename: Michela
authors.initials: M
authors.lastname: Croce
authors.forename: Gaia
authors.initials: G
authors.lastname: Barisione
authors.forename: Claudia
authors.initials: C
authors.lastname: Cossu
authors.forename: Armando
authors.initials: A
authors.lastname: Rossello
authors.forename: Silvano
authors.initials: S
authors.lastname: Ferrini
authors.forename: Marina
authors.initials: M
authors.lastname: Fabbi
mesh_terms: D020410:Activated-Leukocyte Cell Adhesion Molecule / Q000378:metabolism*; D045744:Cell Line, Tumor; D006801:Humans; D009364:Neoplasm Recurrence, Local; D009447:Neuroblastoma / Q000378:metabolism* / Q000473:pathology*; D019581:Neuropil / Q000378:metabolism; D021381:Protein Transport; D012008:Recurrence
chemical_list: D020410:Activated-Leukocyte Cell Adhesion Molecule