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The expression of cytokeratins in Paget cells in mammary and extramammary Paget's disease was studied using different keratin antibodies and immunofluorescence microscopy. Antibodies to epidermal keratin did not react with the Paget cells but stained the surrounding epidermis. Two monoclonal cytokeratin antibodies (PICK1 and RGE53), which reacted typically with simple glandular epithelia in normal tissues, brightly stained the Paget cells and left the surrounding epidermal cells unstained. The results indicate that Paget cells are derived from mammary or sweat duct epithelium rather than from epidermal cells. [ABSTRACT FROM AUTHOR]

We Studied the localization of P230, an immunoanalogue of erythroid α-spectrin, in normal and psoriatic human epidermis and in cultured human keratinocytes. In immunofluorescence microscopy of frozen sections of normal human skin a bright cytoplasmic staining was seen in the cortical area of the keratinocytes. Similar staining was also seen in lesional and uninvolved areas of psoriatic epidermis. The pericytoplasmic localization of P230 could also be seen in cultured human keratinocytes: a lamina-like reticular staining was seen mostly confined to the ventral cytoplasmic aspect and to junctional areas of the cells. Immunoblotting of electrophoretically separated polypeptides of epidermal cells revealed a distinct polypeptide of Mr 230 kD. The results indicate that α-spectrin-like polypeptides form a major cytoskeletal framework in human epidermal ceils in both normal and psoriatic skin. [ABSTRACT FROM AUTHOR]

Surface glycoproteins of cultured human keratinocytes from normal skin and uninvolved psoriatic epidermis, isolated by the suction blister method, were studied by two different methods. Cells were cultured on collagen-coated culture dishes and showed a fibrillar keratin-specific staining by immunofluoresccnce. Surface labelling experiments using the neuraminidase/galactose oxidase/sodium borohydride method (which labels the penultimate galactose moieties of glycoproteins) revealed one major glycoprotein with Mr 53 kD (kilodaltons) both in normal keratinocytes and in keratinocytes from uninvolved psoriatic skin. The periodate/sodium borohydride method (which labels the terminal sialic acids in glycoproteins) by contrast revealed three major glycoproteins, with Mr 53 kD to 63 kD, in normal keratinocytes but only a single major glycoprotein, with Mr 53 kD, in keratinocytes from uninvolved psoriatic skin. Treatment of cultured keratinocytes with etretinate appeared to restore the normal pattern of surface glycoproteins in uninvolved psoriatic keratinocytes. [ABSTRACT FROM AUTHOR]

Sixty-two skin samples from patients with a variety of benign disorders (20 cases of psoriasis, 14 cases of chronic dermatitis, 11 seborrhoeic keratoses. 11 cases of lichen planus), and seven normal skin samples, were stained immunohistochemically with a polyclonal antibody (CM-1) to p 53. and a monoclonal antibody to Ki67. using the avidin—biotin complex method. p53-positive keratinocytes could be found in most of these lesions. The percentage of p53-positive cells was, however, far lower than usually seen in p53-positive malignant tumours. No p53 reactivity was observed in the normal skin samples. Variable Ki67 reactivity was observed in all skin samples. Overall, the number of K167-positive cells was higher in skin samples in which the proportion of p53-positive cells was high (> 0.5% of total epidermal cell population) (P = 0.004). This also applied separately to psoriatic and non-psoriatic lesions (P = 0.028 and P = 0.033, respectively). In cases with > 10% of Ki67-positive cells, there were significantly more mitoses (P < 0.001). This association applied to both psoriasis and the other lesions studied (P = 0.024 and P < 0.001, respectively). The results show that immunohistochemically detectable accumulation of p53 is a frequent finding in non-neoplastic skin lesions. As p53 positivity was associated with the proliferation marker Ki67, the accumulation of p53 is possibly a response to an increased proliferation rate of the keratinocytes in these skin diseases, or alternatively it may be associated with apoptosis. [ABSTRACT FROM AUTHOR]

We studied the localization of p230, an immunoanalogue of erythroid alpha-spectrin, in normal and psoriatic human epidermis and in cultured human keratinocytes. In immunofluorescence microscopy of frozen sections of normal skin a bright cytoplasmic staining was seen in the cortical area of the keratinocytes. Similar staining was also seen in lesional and uninvolved areas of psoriatic epidermis. The pericytoplasmic localization of p230 could also be seen in cultured human keratinocytes: a lamina-like reticular staining was seen mostly confined to the ventral cytoplasmic aspect and to junctional areas of the cells. Immunoblotting of electrophoretically separated polypeptides of epidermal cells revealed a distinct polypeptide of Mr 230 kD. The results indicate that alpha-spectrin-like polypeptides form a major cytoskeletal framework in human epidermal cells in both normal and psoriatic skin.