title: Expression of insulin-like growth factor-binding protein 2 in melanocytic lesions.
abstract: BACKGROUND
  Insulin-like growth factor-1 (IGF-1) is one of the most critical proteins required for the survival, migration, and growth of melanoma cells. IGF-binding protein 2 (IGFBP2), which binds and regulates the function of IGF-1, is upregulated in a dose-dependent manner in melanoma cells treated with IGF-1, suggesting a possible role of IGFBP2 in the pathogenesis of melanoma.
  
  
  METHODS
  Tissue microarrays were constructed using formalin-fixed, paraffin-embedded archival tissue blocks from 94 melanocytic lesions: 20 benign nevi, 20 dysplastic nevi, 23 primary melanomas, and 31 metastatic melanomas. IGFBP2 expression was evaluated immunohistochemically using a polyclonal antibody against the C-terminus of IGFBP2. The number of cells and labeling intensity were assessed semiquantitatively.
  
  
  RESULTS
  Positive IGFBP2 labeling was observed in 5.0% of benign nevi, which was significantly lower than in dysplastic nevi (35.0%), primary melanomas (52.2%), or metastatic melanomas (54.8%) (p < 0.05). Among the IGFBP2-positive cases, moderate-to-strong immunostaining was observed in 64.7% of metastatic melanomas and 33.3% of primary melanomas. But none of the dysplastic nevi had moderate-to-strong immunostaining (p < 0.05).
  
  
  CONCLUSIONS
  Our study shows that IGFBP2 expression increases from benign and dysplastic nevi to primary and metastatic melanomas and suggests that it may play a role in melanoma progression.
authors.affiliation: Department of Pathology and Laboratory Medicine, The University of Texas Medical School at Houston, USA.
authors.forename: Huamin
authors.initials: H
authors.lastname: Wang
authors.forename: Steven S
authors.initials: SS
authors.lastname: Shen
authors.forename: Hua
authors.initials: H
authors.lastname: Wang
authors.forename: A Hafeez
authors.initials: AH
authors.lastname: Diwan
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
authors.forename: Gregory N
authors.initials: GN
authors.lastname: Fuller
authors.forename: Victor G
authors.initials: VG
authors.lastname: Prieto
mesh_terms: D004416:Dysplastic Nevus Syndrome / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D018971:Insulin-Like Growth Factor Binding Protein 2 / Q000378:metabolism*; D008544:Melanocytes / Q000473:pathology; D008545:Melanoma / Q000378:metabolism* / Q000473:pathology / Q000556:secondary*; D009508:Nevus, Pigmented / Q000378:metabolism* / Q000473:pathology; D012878:Skin Neoplasms / Q000378:metabolism* / Q000473:pathology; D013194:Staining and Labeling
chemical_list: D018971:Insulin-Like Growth Factor Binding Protein 2