Abstract: Objective　To detect the expression of stem cell markers P75NTR and SOX2 in ameloblastoma (AM), and to investigate the correlation between tumor stem cells and their biological behavior. Methods 28 AM cases with different types were selected as subjects，and 5 cases of odontogenic cysts and 5 cases of keratocyst were taken as control group. Immunohistochemical staining was used to detect the expression of P75NTR and SOX2, and non-parametric rank-sum test was used to analyze the expression difference of P75NTR and SOX2 between solid AM and unicystic AM, as well as the expression difference between AM and dentigerous cyst and keratocyst. Results The expression intensity of P75NTR in solid AM was significantly higher than that in unicystic AM. The expression intensity of P75NTR in AM was significantly higher than that in dentigerous cyst and keratocyst (P<0.05). These differences showed a statistical meaning. There was no significant difference in SOX2 expression between solid AM and unicystic AM, AM and odontogenic cyst (P > 0.05), and there was difference between AM and keratocyst (P < 0.05). Conclusion The expression of the stem cell marker P75NTR in AM may be related to cell proliferation and stem cell characteristics, and may be involved in tumor invasiveness. SOX2 is less expressed in AM, and its role in AM remains to be further explored.

Key words: ameloblastoma, stem cells, SOX2, P75NTR