Nestin expression in cutaneous melanomas and melanocytic nevi.

BACKGROUND: Nestin is one of the intermediate filaments that are expressed in proliferating neural progenitor cells during development of the central nervous system (CNS) and peripheral nervous system. Postnatal re-expression of the protein occurs mainly under pathological conditions, including injury and neoplasia. In this study, nestin expression was detected in both benign and malignant melanocytic skin lesions and its diagnostic relevance was then evaluated. METHODS: Altogether 139 bioptic tissue samples consisting of 42 nodular melanomas, 32 superficial spreading melanomas, 12 metastatic melanomas, 10 dysplastic nevi and 43 common melanocytic intradermal and dermoepidermal nevi were analysed using indirect immunohistochemical staining. RESULTS: We demonstrated that nestin immunostaining was significantly increased in melanomas where it correlated with more advanced stages of the disease. CONCLUSION: We conclude that expression of the intermediate filament protein nestin might be an indicator of tumor dedifferentiation and more aggressive behaviour. Furthermore, we suggest that nestin might be a relevant marker of tumorous and non-tumorous angiogenesis.

Molecular changes in PDEGF and bFGF in malignant melanomas in relation to the stromal microenvironment.

BACKGROUND: Aberrant expression of either growth factors or growth factor-receptors by stromal cells can be an important factor promoting the growth of solid tumours. It may also affect differentiation of malignant cells and support tumour spread. The aim of the present study was to investigate the hypothesis that basic-fibroblast growth factor (bFGF) and platelet-derived growth factor (PDEGF) may be involved in tumour-stromal microenvironment interactions in primary malignant melanomas. MATERIALS AND METHODS: PDEGF and bFGF expression in malignant cells and surrounding stromal elements was assessed using indirect immunohistochemistry. RESULTS: It was confirmed that PDEGF can be involved in the reciprocal interactions between tumour cells and stroma, including aberrant angiogenesis. Interestingly, bFGF was present both in malignant melanoma lesions and benign nevi accompanied by different intracellular localisation of the protein, suggesting its implication in regulation of nevus cell proliferation and maturation. CONCLUSION: The present results suggest that bFGF and PDEGF participate in malignant melanoma progression.

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.