[The age-related changes of P53 protein expression in oral mucosa and their effects on oral leukoplakia].

OBJECTIVE: To investigate the age-related changes of P53 protein expression in oral mucous membrane and their effects on pathogenesis of the oral precancerous lesions in elderly people. METHODS: An immunohistochemical technique (SP method) was applied to study the changes of P53 expression in normal oral mucosa and oral leukoplakia(OLK) in different age groups. The staining results were evaluated by semi-quantity method. RESULTS: With aging, an elevating tendency of P53 protein level exhibited in the normal oral mucosa and OLK, respectively. The P53 level in the old with OLK was higher than that in the normal oral mucosa of the old (P < 0.01). CONCLUSION: With aging, P53 protein may undergo dysfunction, lead to imperfect DNA repair and excessive DNA damage accumulation, and ultimately facilitate malignant transformation of the oral mucosa in the old.