Altered expression of versican and hyaluronan in melanocytic tumors of dogs.
OBJECTIVE
To analyze the expression of versican and hyaluronan in melanocytomas and malignant melanomas of dogs, to correlate their expression with expression of the hyaluronan receptor CD44, and to identify enzymes responsible for the synthesis and degradation of hyaluronan in canine dermal fibroblasts and canine melanoma cell lines.


METHODS
35 biopsy specimens from melanocytic tumors of dogs, canine primary dermal fibroblasts, and 3 canine melanoma cell lines.


METHODS
Versican, hyaluronan, and CD44 were detected in tumor samples by use of histochemical or immunohistochemical methods. Expression of hyaluronan-metabolizing enzymes was analyzed with a reverse transcriptase-PCR assay.


RESULTS
Versican was found only in some hair follicles and around some blood vessels in normal canine skin, whereas hyaluronan was primarily found within the dermis. Hyaluronan was found in connective tissue of the oral mucosa. Versican and, to a lesser extent, hyaluronan were significantly overexpressed in malignant melanomas, compared with expression in melanocytomas. No significant difference was found between malignant tumors from oral or cutaneous origin. The expression of both molecules was correlated, but hyaluronan had a more extensive distribution than versican. Versican and hyaluronan were mainly associated with tumor stroma. Canine fibroblasts and melanoma cell lines expressed hyaluronan synthase 2 and 3 (but not 1) and hyaluronidase 1 and 2.


CONCLUSIONS
Versican may be useful as a diagnostic marker for melanocytic tumors in dogs. Knowledge of the enzymes involved in hyaluronan metabolism could reveal new potential therapeutic targets.
Departament de Bioquímica i Biologia Molecular, Facultat de Veterinària, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain.
María-José
MJ
Docampo
Rosa M
RM
Rabanal
Laia
L
Miquel-Serra
Daniel
D
Hernández
Clelia
C
Domenzain
Anna
A
Bassols
D000818:Animals; D045744:Cell Line, Tumor; D004283:Dog Diseases / Q000378:metabolism*; D004285:Dogs; D005347:Fibroblasts / Q000378:metabolism; D015972:Gene Expression Regulation, Neoplastic; D018960:Hyaluronan Receptors / Q000378:metabolism; D006820:Hyaluronic Acid / Q000235:genetics / Q000378:metabolism*; D007527:Isoenzymes; D008545:Melanoma / Q000378:metabolism / Q000662:veterinary*; D053675:Versicans / Q000235:genetics / Q000378:metabolism*
D018960:Hyaluronan Receptors; D007527:Isoenzymes; D053675:Versicans; D006820:Hyaluronic Acid