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.

Pathobiology of androgenetic alopecia.

Human hair morphogenesis is a dynamic process caused by the remodelling of the skin. Hair growth is cyclic in mammals consisting of three distinct stages: an active stage (anagen), a regressive stage (catagen), and a resting stage (telogen). One disorder in this process is gradual balding of the scalp called androgenetic alopecia. Little is known about the cell biological or molecular mechanisms involved and thus very little treatment is currently available. In this review we focus on the most significant parameters affecting hair growth which participate in baldness.

Fluridil, a rationally designed topical agent for androgenetic alopecia: first clinical experience.

BACKGROUND: Fluridil, a novel topical antiandrogen, suppresses the human androgen receptor. While highly hydrophobic and hydrolytically degradable, it is systemically nonresorbable. In animals, fluridil demonstrated high local and general tolerance. OBJECTIVE: To evaluate the safety and efficacy of a topical anti- androgen, fluridil, in male androgenetic alopecia. METHODS: In 20 men, for 21 days, occlusive forearm patches with 2, 4, and 6% fluridil, isopropanol, and/or vaseline were applied. In 43 men with androgenetic alopecia (AGA), Norwood grade II-Va, 2% fluridil was evaluated in a double-blind, placebo-controlled study after 3 months clinically by phototrichograms, hematology, and blood chemistry including analysis for fluridil, and at 9 months by phototrichograms. RESULTS: Neither fluridil nor isopropanol showed sensitization/irritation potential, unlike vaseline. In all AGA subjects, baseline anagen/telogen counts were equal. After 3 months, the average anagen percentage did not change in placebo subjects, but increased in fluridil subjects from 76% to 85%, and at 9 months to 87%. In former placebo subjects, fluridil increased the anagen percentage after 6 months from 76% to 85%. Sexual functions, libido, hematology, and blood chemistry values were normal throughout, except that at 3 months, in the spring, serum testosterone increased within the normal range equally in placebo and fluridil groups. No fluridil or its decomposition product, BP-34, was detectable in the serum at 0, 3, or 90 days. CONCLUSION: Topical fluridil is nonirritating, nonsensitizing, nonresorbable, devoid of systemic activity, and anagen promoting after daily use in most AGA males.