EXPRESSION OF P53, KI-67 AND CYTOKERATIN-4 (CK4) IN ORAL PAPILLOMAS

P53 is overexpressed in more than 50% of all human cancers. A previous study suggested that p53 was also overexpressed in oral papillomas. T his study was carried out to investigate whether p53 expression was co rrelated with expression of the cellular proliferation marker Ki-67 an d the epithelial differentiation marker cytokeratin-4 (CK4) in oral pa pillomas. Formalin-fixed paraffin-embedded sections of 30 oral papillo ma specimens and 30 unmatched normal oral mucosal specimens were proce ssed for immunohistochemistry, using an avidin-biotin- peroxidase proc edure and monoclonal antibodies. A semiquantification analysis on p53 and Ki-67 labeling indices was performed. Twenty-eight of 30 (93%) pap illoma specimens were positive for p53. The percentage of p53-positive cells in the basal layer was 60.4+/-14.8 (mean+/-SD, n=28), and that of Ki-67-positive cells was 26.7+/-14.4. There was no correlation betw een expression of p53 and that of Ki-67. Expression of CK4 was inverse ly correlated with the expression of Ki-67 but not correlated with the expression of p53.