Cancer stem cell markers, SOX 2 and OCT 4 in ameloblastoma and keratocystic odontogenic tumor: An immunohistochemical study

Abstract

Background: SOX 2 and OCT 4 are cancer stem cell (CSC) markers required for the maintenance of pluripotency and self-renewal of stem cells. They have been found to play a role in tumorigenesis. This study was conducted to detect and compare the expression of CSC markers OCT 4 and SOX 2 in ameloblastoma and keratocystic odontogenic tumor (KCOT) and to evaluate which marker better stains the stem cell population in the above-mentioned entities. Materials and Methods: Paraffin sections of 15 KCOT's and 15 solid multicystic ameloblastomas were obtained from the archives. Immunohistochemical staining for OCT 4 and SOX 2 was performed using monoclonal rabbit antibodies (PathnSitu Biotechnologies Pvt. Ltd). Immunopositivity was determined on the basis of dark brown staining of nucleus and a total of 1000 cells were counted in five representative areas at a magnification of ×400. Results: No OCT 4 positivity was found in ameloblastoma or KCOT. Ameloblastoma showed SOX 2 negativity while high SOX 2 expression was found in KCOT. Conclusion: SOX 2 is a more reliable marker for identifying stem cell population in KCOT. High expression pattern of SOX 2 in KCOT may also explain the aggressive nature of lesion and account for the presence of numerous daughter cysts responsible for its high recurrence rate, and hence, may be helpful to justify its reclassification as a tumor. Targeted therapies may be designed against these CSC populations to render more effective treatment, prevent recurrence, and reduce morbidity of the patients.