Expression of insulin-like growth factor-binding protein 2 in melanocytic lesions.
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.
Wang
Huamin
H
Department of Pathology and Laboratory Medicine, The University of Texas Medical School at Houston, USA.
Shen
Steven S
SS
Wang
Hua
H
Diwan
A Hafeez
AH
Zhang
Wei
W
Fuller
Gregory N
GN
Prieto
Victor G
VG
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
D018971:Insulin-Like Growth Factor Binding Protein 2