title: Aberrant accumulation of p53 associates with Ki67 and mitotic count in benign skin lesions.
abstract: 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 p53, 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 Ki67-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.
authors.affiliation: Department of Pathology, University of Oulu, Finland.
authors.forename: Y
authors.initials: Y
authors.lastname: Soini
authors.forename: D
authors.initials: D
authors.lastname: Kamel
authors.forename: P
authors.initials: P
authors.lastname: Pääkkö
authors.forename: V P
authors.initials: VP
authors.lastname: Lehto
authors.forename: A
authors.initials: A
authors.lastname: Oikarinen
authors.forename: K V
authors.initials: KV
authors.lastname: Vähäkangas
mesh_terms: D001623:Betamethasone / Q000494:pharmacology; D002452:Cell Count; D002455:Cell Division; D003872:Dermatitis; D006801:Humans; D007150:Immunohistochemistry; D017492:Keratosis, Seborrheic; D019394:Ki-67 Antigen; D008010:Lichen Planus; D008297:Male; D009363:Neoplasm Proteins / Q000032:analysis*; D009687:Nuclear Proteins / Q000032:analysis*; D011565:Psoriasis; D012867:Skin / Q000737:chemistry* / Q000187:drug effects / Q000276:immunology / Q000473:pathology; D012871:Skin Diseases / Q000473:pathology; D016159:Tumor Suppressor Protein p53 / Q000032:analysis*
chemical_list: D019394:Ki-67 Antigen; D009363:Neoplasm Proteins; D009687:Nuclear Proteins; D016159:Tumor Suppressor Protein p53; D001623:Betamethasone