Immunohistochemical assessment of E-cadherin and beta-catenin in trichofolliculomas and trichoepitheliomas.

BACKGROUND: Trichofolliculomas and trichoepitheliomas are benign skin neoplasms originating from hair follicle cells. They result from defects in the signaling pathways that regulate hair follicle morphogenesis and regeneration. Thus they seem to be an excellent model of these processes. It is known that the E-cadherin/beta-catenin system of adhesion molecules plays a crucial role in the maintenance of tissue architecture. AIM: The aim of the present study was to investigate their involvement in benign hair follicle tumor development. METHODS: Semiquantitative intensity of expression were examined in formalin-fixed and paraffin-embedded tissue sections of 53 trichoepitheliomas, 15 trichofolliculomas and 19 normal skin samples by indirect immunohistochemistry. RESULTS: The intensity of E-cadherin/beta-catenin expression in tumor cells did not differ from controls. However, normal hair follicles cells exhibited membranous E-cadherin/beta-catenin expression, whereas both types of tumors, particularly trichoepitheliomas, showed E-cadherin/beta-catenin expression with a predominantly cytoplasmic localization. CONCLUSIONS: We suggest that this dystopic distribution of the E-cadherin/beta-catenin complex in hair follicle tumor cells may be a marker of cell-cell adhesion disruption which may contribute to the tumor formation.

Expression of beta-catenin, p63 and CD34 in hair follicles during the course of androgenetic alopecia.

During the hair growth cycle, the hair follicle appears to recapitulate part of its embryogenesis where both beta-catenin and p63 participate. The aim of the present study was to investigate the hypothesis that beta-catenin and p63 protein may be involved in the pathogenesis of androgenetic alopecia. Second, expression of CD34 protein was used to assess the capillary density of the affected skin. Cadavers were used as samples and the results showed that analysis of beta-catenin, p63 and CD34 expressions in human cadaverous scalp skin by immunohistochemical techniques were possible. We detected a higher expression of p63 in occipital skin in comparison to the affected frontal areas. However, we found only minimal changes in beta-catenin expression comparing frontal and occipital areas. A completely new finding was the expression of CD34 positive cells in the outer root sheath of hair follicles.

Androgenetic alopecia and current methods of treatment.

Androgenetic alopecia (AGA) is a common dermatological condition affecting both men and women. In the case of men, up to 30% over the age of 30 and more than 50% over the age of 50 are affected. AGA also affects women although clinical signs are usually milder and associated with diffuse thinning of the scalp hair. AGA invariably causes serious psychological problems especially in women. By far the most promising approaches to the treatment of baldness in men are drug therapies, such as topical minoxidil and finasteride administered systemically. Mild to moderate AGA in women can be treated with antiandrogens and/or topical minoxidil with good results in many cases.