p53 protein expression in odontogenic cysts

p53 protein seems to be related to the suppression of cell proliferation. p 53-positive tissues seem to have a higher proliferative activity than p53-n egative ones. Odontogenic keratocyst (OKC) has a different behavior from ot her types of cysts because it is more aggressive, with a tendency to recurr ence. Twenty-two dentigerous cysts, 24 radicular cysts, and 20 OKCs were us ed in the present study. Two dentigerous cysts (9,1%), 2 radicular cysts (8 ,3%), and 9 OKCs (45%) expressed the p53 protein. The differences between t he three groups were statistically significant (p = 0,003). In 10 cases of OKCs epithelial dysplasia was found. One of the 10 OKCs without dysplasia a nd 8 of the 10 OKCs with dysplasia were p53-positive: the difference betwee n the two groups was statistically significant (p = 0,007). The overexpress ion of p53 protein was not on the other hand correlated with the occurrence of multiple, bilateral, and recurrent OKCs, Moreover the distribution of p 53-positive cells was parabasal in contrast with other types of cysts. Thes e qualitative and quantitative differences in proliferative activity in OKC s seem to point to an alteration in cell cycle control.