[Expression of p53 in the skin in systemic sclerosis. Immunohistochemical study of 8 cases].

P53 gene belongs to the family of "Tumor suppressor gene". It encodes a nuclear phosphoprotein involved in cell proliferation control; mutations of p53 gene are the most common genetic alterations found in human tumors. These mutations may cause the production of an altered protein that usually loses its physiological function. The mutant p53 protein is more stable than the wild type form and it is immunohistochemically detectable. Systemic Sclerosis is characterized by activation of fibroblasts, endotheliocytes and lymphocytes; furthermore, in this disease, a proto-oncogenic activation has already been shown in fibroblasts and lymphocytes. The aim of this study was to verify p53 expression in the skin of SSc patients. Eight patients, all classified in the limited cutaneous subset of SSc, after informed consent, underwent skin biopsies of the affected and apparently unaffected skin. P53 was investigated by immunohistochemistry, using a monoclonal anti-p53 antibody (DO-7), on formalin fixed, paraffin embedded tissue. P53 immunoreactive cells were found in 4 out of 8 biopsies; in all cases the positivity was confined to cells of the basal layer of the epidermis, histologically identified as keratinocytes. A large case series and a molecular biology approach are needed to support these preliminary observations.