p120 and AgNOR nucleolar protein expression: a comparison with nuclear proliferation markers in oral pathology.

To find a better method for predicting the biological behavior of certain oral cavity lesions, the expression of nucleolar protein p120 and nucleolar organizer region counts (AgNOR) was compared with that of nuclear proliferation markers MIB-1 and PCNA in 10 cases of keratotic epithelial hyperplasia (KEH), 10 cases of epithelial dysplasia (ED), and 15 cases of squamous cell carcinoma (SCC). Significant differences in p120 and AgNOR mean area values and PCNA labeling index (LI) were recorded between KEH and ED, as well as ED and SCC (Student-Neumann-Keuls test). All markers significantly differed between SCC grades I and III. Significant differences were also noted in AgNOR mean area values between grade I and II SCC and in p120 mean area values. MIB-1 and PCNA LI differed significantly when grade II and III SCC were compared (SNK test). There were significant correlations between p120 and AgNOR (Pearson correlation coefficients) and between both of them and the proliferative indexes. AgNOR correlated with tumor grade, stage, and lymph node status (Spearman correlation coefficients), suggesting a prognostic role for that marker.