The Co-expression of c-myc and p53 Increases and Reaches a Plateau Early in Oral Oncogenesis

Abstract

Background: The balance between cell proliferation and apoptosis plays a significant role in cancer development. The expressions of the p53 and c-myc genes, both strongly related to cell proliferation and apoptosis, were studied in sequential histological grades of oral carcinogenesis in an animal model. Materials and Methods: Thirty-seven hamsters were divided into three groups (A,B,C), which were treated with 9,10-dimethyl-1,2-benzanthracene and sacrificed at 10,14 or 19 weeks, respectively, after treatment. The histological status of the oral lesions in the experimental groups corresponded well with tumour advancement (from dysplasia to moderately-differentiated carcinoma). Tumour sections were studied immunohistochemically. Results: The expressions of both p53 and c-myc increased significantly in precancer stages and then reached a plateau. The same pattern was observed in the animal groups with the culmination of expression of both genes in group A. Conclusion: The co-expression of p53 and c-myc proteins in the earlier stages of oral oncogenesis may be used for the early detection of premalignant lesions.