Expression of neurotrophin receptor Trk-C in nevi and melanomas.
BACKGROUND
Neurotrophins (NTs) are growth factors for neurons and other neural crest-derived cells. Their functions are mediated by 75-kDa low-affinity glycoprotein receptor (p75) NT receptor and a family of tyrosine kinase receptors (Trks) that includes Trk-A, -B, and -C. Signal transduction through the Trk receptors has been shown to regulate growth and apoptosis of tumors of neuronal origin. In addition, Trk oncogenes have been shown to be rearranged in some non-neuronal neoplasms. Recently, immunoexpression of NT-3 has been shown to be significantly higher in melanomas than in banal nevi on cryostat tissue.


METHODS
Since the biologic function of NT-3 is mediated primarily through Trk-C, we investigated Trk-C immunoexpression on paraffin sections of 10 compound nevi and 63 melanomas.


RESULTS
The expression of Trk-C was relatively low in compound nevi (30%). Trk-C expression was overall 62% in melanomas of various stages. Our data show that the expression of Trk-C increased as melanoma progressed from in situ (58%) to papillary dermal invasion (91%), and then declined in deeper (57%) and metastatic melanomas (31%).


CONCLUSIONS
These findings suggest a possible role of Trk-C in the progression of early stages of melanoma.
Xu
Xiaowei
X
Hospital of University of Pennsylvania, Philadelphia, PA, USA.
Tahan
Steven R
SR
Pasha
Terri L
TL
Zhang
Paul J
PJ
D014408:Biomarkers, Tumor / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D008545:Melanoma / Q000145:classification / Q000378:metabolism* / Q000556:secondary; D009367:Neoplasm Staging; D009506:Nevus / Q000378:metabolism* / Q000473:pathology; D020812:Receptor, trkC / Q000378:metabolism*; D012878:Skin Neoplasms / Q000145:classification / Q000378:metabolism* / Q000473:pathology
D014408:Biomarkers, Tumor; D020812:Receptor, trkC