title: Galectin-3 as a marker distinguishing functioning from silent corticotroph adenomas.
abstract: OBJECTIVE
  Galectin-3 (Gal-3) belongs to the family of carbohydrate-binding proteins with high affinity for galactoside and is involved in many biological processes including cell growth and differentiation, cell adhesion, tumor progression, apoptosis and metastasis. The aim of this study was to disclose differences in the expression of Gal-3 in silent and functioning corticotroph pituitary adenomas.
  
  
  METHODS
  We examined 30 pituitary adenomas (19 functioning corticotroph, 11 silent corticotroph adenomas). Two prolactinomas and 2 functioning somatotroph adenomas served as positive controls. Antigen retrieval was done by three-minute incubation via pressure boiler in citrate buffer solution, pH 6.0. A polymer was used as a secondary link to DAB chromogen. The independent variables t-test was used for comparison of the mean expression of Gal-3 in the two different corticotroph adenoma subgroups.
  
  
  RESULTS
  Eighteen of the functioning corticotroph adenomas (94.73%) were positive for Gal-3 with a cytoplasmic and focally membranous distribution; two cases also exhibited nuclear expression, whereas 9 of the silent corticotroph adenomas (81.81%) had zero or<1% expression of Gal-3 (p=0.001).
  
  
  CONCLUSIONS
  Gal-3 is highly expressed in functioning corticotroph adenomas of the pituitary gland, while silent adenomas exhibit very focal to null expression of Gal-3. This observation can be used in the pathological diagnosis to separate functioning from silent corticotroph adenomas of the pituitary.
authors.affiliation: Department of Pathology and Pituitary Tumor Reference Center, G. Gennimatas Athens General Hospital, Athens, Greece.
authors.forename: Eleni
authors.initials: E
authors.lastname: Thodou
authors.forename: Theodore
authors.initials: T
authors.lastname: Argyrakos
authors.forename: George
authors.initials: G
authors.lastname: Kontogeorgos
mesh_terms: D049913:ACTH-Secreting Pituitary Adenoma / Q000175:diagnosis* / Q000473:pathology; D000236:Adenoma / Q000175:diagnosis* / Q000473:pathology; D014408:Biomarkers, Tumor / Q000378:metabolism*; D037502:Galectin 3 / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D010902:Pituitary Gland / Q000378:metabolism
chemical_list: D014408:Biomarkers, Tumor; D037502:Galectin 3