The role of MDM2 in the proliferative activity of ameloblastoma

Ameloblastoma is a unique tumor in the oral and maxillofacial region with various levels of proliferative activity in each type. p53 is most commonly found to be mutated in human cancer and sometimes is overexpressed also in other lesions, such as ameloblastoma. Murine Double Minute 2 (MDM2) is able to physically associate with the p53 tumor suppressor and therefore block the growth suppressive functions of p53. In the present study, immunohistochemistry, western blotting and enzyme-linked immunosorbent assay for p53 mutant selective test were done. MDM2 was overexpressed in ameloblastoma and the results showed different numbers of MDM2 labeling index based on both WHO classification and cytological pattern of outer layer cells. Basal ameloblastoma, which has a high proliferative activity, had the highest MDM2 labeling index. We suggest MDM2 protein caused the high proliferative activity of ameloblastoma, especially in basal cell ameloblastoma.