Expression of Fas and Fas Ligand in Various Skin Diseases

Lee, Jee Bum; Lee, Seung Chul; Won, Jee Youn; Song, Eun Sub; Won, Young Ho

Abstract

BACKGROUND: Fas and Fas ligand (FasL) are cell surface proteins that mediate apoptosis. Fas and FasL are expressed in normal epidermal cells, but are different in the expression patterns in epidermal layers.
OBJECTIVE
The purpose of this study was to evaluate the expression of Fas and FasL in various skin diseases including non-tumorous diseases and tumors. METHOD: We performed immunohistochemical staining for Fas and FasL with monoclonal or polyclonal antibodies using frozen skin tissues from 29 patients.
RESULTS
1. In normal skin, Fas and FasL were expressed as intercellular and intracellular patterns. Fas was expressed in the basal and spinous layers, and FasL was expressed in the upper spinous and granular layers. 2. In psoriasis vulgaris and lichen planus, FasL expression was proportional to the degree of epidermal hyperplasia, such a relationship was not found in Fas expression. 3. In verruca vulgaris and herpes zoster, the upregulation of Fas and FasL expression was observed in lesional epidermis. 4. In skin tumors, Fas and FasL expression were observed in most tumor cells of Bowen's disease, keratoacanthoma, and squamous cell carcinoma. In basal cell carcinoma, FasL was expressed strongly and diffusely in the infiltrating tumor cells, but Fas was not expressed at all.
CONCLUSION
Fas and FasL play an important role in the differentiating process of the epidermis by coordinate expression between them. In non-tumorous conditions and skin tumors, Fas and FasL might function as essential mediators of cellular turnover in pathogenesis of the skin diseases.