IMP-3 is a novel progression marker in malignant melanoma.
Insulin-like growth factor-II messenger RNA (mRNA)-binding protein-3 (IMP-3), also known as K homology domain-containing protein overexpressed in cancer (KOC) and L523S, is a member of the insulin-like growth factor-II mRNA-binding protein family and is expressed during embryogenesis and in some malignancies. IMP-3 expression in melanocytic neoplasms has not been investigated. Fifty-six melanocytic neoplasms from 48 subjects were immunohistochemically studied using a monoclonal antibody against L523S/IMP-3. IMP-3 expression in melanoma was significantly higher than in Spitz nevi (P<0.05), and the staining intensity in the Spitz nevi was weak. IMP-3 expression in metastatic melanoma was significantly higher than in primary cutaneous melanoma with a Breslow depth </=1 mm (P<0.01). None of the benign nevi and dysplastic nevi expressed IMP-3. Our study demonstrates that IMP-3 is expressed in malignant melanoma but not in benign nevi, even when dysplastic features are present; IMP-3 is expressed in a significantly higher proportion of melanomas than Spitz nevi; and IMP-3 is expressed in metastatic melanomas significantly more than in thin melanomas. In conclusion, IMP-3 appears to be involved in the progression of malignant melanoma and may play an important role in the regulation of the biologic behavior of this tumor. Additionally, IMP-3 may have diagnostic utility in distinguishing melanoma from benign nevic cells, dysplastic nevi, and Spitz nevi.
Pryor
Jennifer G
JG
Department of Pathology and Laboratory Medicine, University of Rochester School of Medicine and Dentistry, Rochester, NY 14642, USA.
Bourne
Patricia A
PA
Yang
Qi
Q
Spaulding
Betsy O
BO
Scott
Glynis A
GA
Xu
Haodong
H
D000293:Adolescent; D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000032:analysis*; D003937:Diagnosis, Differential; D018450:Disease Progression; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008545:Melanoma / Q000378:metabolism* / Q000473:pathology*; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000378:metabolism*; D009506:Nevus / Q000378:metabolism / Q000473:pathology; D011230:Precancerous Conditions / Q000378:metabolism / Q000473:pathology; D016601:RNA-Binding Proteins / Q000378:metabolism*; D012878:Skin Neoplasms / Q000378:metabolism* / Q000473:pathology*
D014408:Biomarkers, Tumor; C498780:IGF2BP3 protein, human; D009363:Neoplasm Proteins; D016601:RNA-Binding Proteins