John Libbey Eurotext




Retinoic‐acid receptor β expression in melanocytes
European Journal of Dermatology. Volume 14, Number 1, 19-23, January-February 2004, Investigative report
Free Article
Author(s) : Nelly BOEHM, Brigitte SAMAMA, Bernard CRIBIER, Cécile ROCHETTE‐EGLY
Summary : Retinoic acid receptors (RAR) and retinoic X receptors (RXR) are critical for skin homeostasis. In epidermis, RXRα and RARγ isoforms are highly expressed but only weak or no expression of RARβ has been reported. Here, we re‐examined RARβ in situ expression in comparison with that of the RXRα, in both normal skin and melanocytic tumours. In normal skin, RXRα was localized in epidermis, sebaceous glands and hair follicles, while RARβ was detectable only in melanocytes and in stratum granulosum. RXRα was never detected in melanocytic tumours, neither in nevi, nor in melanomas. RARβ was also absent from melanoma cells but was present in nevus cells. These results indicate that melanoma are characterised by simultaneous decrease of RARβ and absence of RXRα that may be responsible for the RA‐resistance of most melanoma cell lines.
Keywords : Immunocytochemistry, melanocyte, melanoma, retinoic acid receptors, RXRα, RARβ

Retinoic‐acid receptor β expression in melanocytes