Expression of ATM, p53 and MDM2 in Oral Leukoplakia

Abstract

The correlation of epithelial dysplasia (ED) with the expression of p53, ATM and MDM2 was examined immunohistochemically in 107 cases of oral leukoplakia (OL). In addition, in situ hybridization was used to investigate the localization of ATM and MDM2 genes. OLs consisted of 9 cases with non-ED, 35 cases with mild ED, 30 cases with moderate ED and 33 cases with severe ED. In addition, 22 cases with normal oral epithelium and 19 cases with oral squamous cell carcinoma were used as controls. The results revealed that the positive rate of p53 was significantly higher in OL with severe ED than in normal oral epithelium. Although the positive cells for ATM were most frequently seen in OL with mild ED, its positive rate was not significantly different from that of normal oral epithelium. The positive rate of MDM2 was significantly higher in OL with mild, severe ED and oral squamous cell carcinoma than in normal oral epithelium. ATM and MDM2 genes were mainly detected in the basal cell layer and prickle cell layer, respectively. The localization of these genes was consistent with that of their proteins.