evaluation of p53 and pcna expression in oral leukoplakic lesions with and without epithelial dysplasia by immunohistochemistry technique

introduction: leukoplakia is the most common precancerous lesion of the oral mucosa and may range microscopically form benign hyperkeratosis to invasive squamous cell carcinoma. p53 is a tumor suppressor protein; whereas, proliferative cell nuclear antigen (pcna) is a proliferative marker. the aim of this study was to evaluate the immunohistochemical expressions of p53 and pcna in oral leukoplakia with and without dysplasia. materials & methods: the expression of p53 and pcna proteins were determined immunohistochemically in paraffin sections of 53 leukoplakias (17 without dyplasia, 15 with mild dysplasia, 14 with moderate dysplasia and 7 with severe dysplasia), in addition to 10 normal oral mucosa. statistical analysis was performed using one-way anova, kruskal-wallis, and spearman tests. results: p53 protein was expressed in 60% of normal oral mucosa, 82.4% of leukoplakias without dysplasia and 100% of leukoplakias with dysplasia. pcna protein was expressed in all of the specimens. there were statistical differences between p53 and pcna expression among normal mucosa, leukoplakias with and without dysplasia, regarding their grading and severity (p< 0.001). there was a positive correlation between p53 and pcna expression. conclusion: increase in p53 and pcna expression is related to the degree of dysplasia in oral leukoplakias. therefore, we can use these markers in order to indicate and grade dysplastic lesions more exactly. pcna and p53 could also be used as appropriate markers to estimate the potential of malignant transformation in oral leukoplakia lesions.