Comparison of C-Myc Oncogene Expression in Benign and Malignant Odontogenic Tumors

Aims: The aim of this study was to comparatively investigate the expression of c-Myc oncoprotein in benign and malignant odontogenic tumors and also to assess its potential prognostic role in these conditions.
Study Design: The c-Myc protein is a nuclear transcription factor which centrally regulates cell proliferation, arrest, cell differentiation and cell death. Ameloblastomas are benign uncommon tumors. They are the most frequently encountered odontogenic tumors arising from the epithelium of the odontogenic apparatus. They rarely have the potentiality to turn malignant in the form of either malignant ameloblastoma or ameloblastic carcinoma. The expression of c-Myc oncogene products were detected in normal tissue and cancer cells. It is related to the proliferation of odontogenic epithelial cells and its degree of differentiation.
Materials and Methods: Eleven cases of amelobastomas were included in this study. Six cases were benign and five cases were malignant ameloblastomas. All the specimens were retrieved from Alexandria University, Maxillofacial and Oral Pathology department. Biopsy specimens were prepared, fixed in paraffin wax and processed for immunohistochemical staining using the standard streptavidin Biotin peroxidase complex method, and the primary monoclonal antibody specific for c-Myc.
Results: Results revealed strong staining reaction of the nucleus and cytoplasm of the peripheral columnar cells and to a lesser extent in the polyhedral cells. The intensity of the reaction was stronger in malignant cases and mild in the benign cases.
Conclusion: Immunoreactivity of the c-Myc oncogene was directly proportional with the degree of malignancy and was a valuable marker for elucidating the mode of growth and development of odontogenic epithelial cells from the pathological point of view.