The expression and significance of Ki-67 and Cox-2 in the oral mucosa of healthy people

Objective To evaluate the expressions of Ki-67 and Cox-2 in relation to histological changes of the oral mucosa of healthy people and the potential possibility of incidence of oral mucosa disease.Methods Fifty samples of oral mucosa from 50 volunteers of healthy people and 10 samples of leukoplakia from clinical patients were enrolled in this study. Tissue sections were prepared from formalin-fixed/paraffin-embedded specimens. Immunostainings against Ki-67 and Cox-2 antibodies were carried out by using polymer method as described in the kit's instruction sheet. All data were dealt statistically with SPSS 10.0.Results Oral mucosa of 50 healthy people showed grossly ruddy and soft,but only 10 samples out of 50 healthy people showed histologically normal mucosa,other 40 samples showed epithelial hyperplasia and edema similar to the histopathology of leukoedema. Ten cases of leukoplakia showed epithelial hyperplasia and hyperorthokeratosis. Immunohistochemically,nuclear Ki-67 expressions were positively identified in 10 normal mucosa (5.24%),in 40 epithelial hyperplasia and edema (14.41%) and in 10 leukoplakia (12.08%). There was significantly different between the normal mucosa and both epithelial hyperplasia and leukoplakia (P0.05),whereas no significant difference was noted between epithelial hyperplasia and leukoplakia (P0.05). The expression of Cox-2 was gradually increased from 10 normal mucosa (0%) to 40 epithelial hyperplasia (55.0%) and 10 leukoplakia (70.0%),there was statistically different between the normal mucosa and both epithelial hyperplasia and leukoplakia (P0.05),and no any significant difference was found between epithelial hyperplasia and leukoplakia (P0.05).Conclusion Nearly 80% oral mucosa of healthy people in this study showed the histopathological changes.