Immunohistochemical expression of matrix metalloproteinase-2 and -9 in melanocytic nevi is altered by ultraviolet B.
BACKGROUND
Ultraviolet B (UVB) radiation can cause morphological and biological alterations similar to those of melanoma in situ in irradiated melanocytic nevi. matrix metalloproteinase (MMP-2) and -9 appear to be involved with tumour invasion, the formation of metastases and neoangiogenesis in melanomas. The effects of UVB on the immunohistochemical expression of gelatinases in different cell types in melanocytic nevi have not been completely studied.


OBJECTIVE
Evaluate the effects of UVB on the immunohistochemical expression of MMP-2 and -9 in different cell types in melanocytic nevi.


METHODS
Forty-two melanocytic nevi had one half irradiated with 2 MEDs of UVB and were excised 1 week later. Three different observers compared the intensity of the immunohistochemical expression of gelatinases in keratinocytes, melanocytes, endothelial cells and fibroblasts on the irradiated (IS) and non-irradiated sides (NIS).


RESULTS
All the cell types showed an increase in the expression of MMP-2 on the IS, especially the epidermal melanocytes. No significant increase in the expression of MMP-9 in keratinocytes was detected on the IS; significant increase was observed in all the remaining cells.


CONCLUSIONS
One single irradiation of UVB increases the immunohistochemical expression of gelatinases in almost all evaluated cell lines, with the exception of MMP-9 in keratinocytes.
Bakos
Renato Marchiori
RM
Department of Dermatology, Hospital de Clínicas de Porto Alegre, Federal University of Rio Grande do Sul, Porto Alegre, Brazil. rbakos@portoweb.com.br
Bakos
Lucio
L
Edelweiss
Maria Isabel Albano
MI
Cartell
André
A
Mariante
José Carlos
JC
Masiero
Nathália Costaguta Matas Soles
NC
D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism*; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism*; D009508:Nevus, Pigmented / Q000201:enzymology*; D012867:Skin / Q000201:enzymology / Q000528:radiation effects; D014466:Ultraviolet Rays
D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9