vitamin-a2 and Skin-Diseases

Retinoids are biologic response modifiers that are present in normal skin and may possibly be perturbed in carcinogenesis. To examine this possibility in human skin, we analyzed vitamin A and cytosolic retinoid binding proteins (cellular retinol binding protein and cellular retinoic acid binding protein [CRABP]) in a total of 38 non-melanoma skin tumors and 25 healthy skin samples using high performance liquid chromatography, radioligand electrophoresis, and reverse transcriptase-polymerase chain reaction. The mean +/- SEM retinol concentration was normal in basal cell carcinoma (0.60 +/- 0.10 microM) and seborrheic keratosis (0.47 +/- 0.07 microM), but increased in keratoacanthoma (1.60 +/- 0.41 microM) and squamous cell carcinoma (1.17 +/- 0.28 microM) (p < 0.05 for both). Also, the concentrations of 3,4-didehydroretinol, a major vitamin A metabolite produced in human skin, were markedly elevated (6-7 times normal) in keratoacanthoma and squamous cell cancer. All types of tumors showed moderately increased levels of cellular retinol binding protein. In addition, keratoacanthoma and squamous cell cancer showed markedly increased levels (6-7 times normal) of CRABPII protein. Transcriptional activity of the CRABPII gene was demonstrated in both normal and neoplastic epidermis, but clear CRABPI mRNA expression was found only in basal cell carcinoma. The data indicate that characteristic perturbations of the vitamin A and retinoid binding protein levels occur in squamous cell-derived skin tumors, but whether these reflect intrinsic errors in retinoid metabolism or are secondary to abnormal cellular differentiation is unknown.

Topics: Aged; Aged, 80 and over; Carcinoma, Basal Cell; Carcinoma, Squamous Cell; Humans; Keratoacanthoma; Middle Aged; Receptors, Retinoic Acid; Retinol-Binding Proteins; Retinol-Binding Proteins, Cellular; RNA, Messenger; Skin Diseases; Skin Neoplasms; Vitamin A

The concentrations of vitamin A and total carotenoids were measured in serum and skin of 61 patients with acne vulgaris, atopic dermatitis, ichthyosis vulgaris or lichen planus, and compared with those in 37 healthy subjects. The mean serum concentrations of retinol and retinol-binding protein were significantly decreased in patients with acne (P less than 0.01) and slightly increased in those with ichthyosis (P less than 0.05), but were otherwise normal. Serum carotenoid levels did not differ between patients and controls. Superficial shave biopsies from both involved and uninvolved skin were examined for the presence of retinol (vitamin A1), dehydroretinol (vitamin A2) and total carotenoids. The mean retinol concentration was increased in lichen planus lesions (P less than 0.05) and decreased in both acne skin (involved and uninvolved) and in lesions of atopic dermatitis (P less than 0.05). The mean dehydroretinol concentration was markedly increased in lesions of atopic dermatitis and lichen planus (P less than 0.01). No consistent abnormalities were found in skin of patients with ichthyosis vulgaris. The mean carotenoid concentration in the patients' skin did not differ significantly from that in the controls. The reduced retinol level in the skin of acne patients is probably explained by diminished supply of vitamin A from the blood. The abnormal ratio of retinol to dehydroretinol in lesions of lichen planus and atopic dermatitis is possibly due to changes in cutaneous vitamin A metabolism associated with epidermal hyperproliferation and inflammation.

Topics: Acne Vulgaris; Adolescent; Adult; Aged; Carotenoids; Dermatitis, Atopic; Female; Humans; Ichthyosis; Lichen Planus; Male; Middle Aged; Retinol-Binding Proteins; Skin; Skin Diseases; Vitamin A