Nucleostemin Expression in Squamous Cell Carcinoma of the Head and Neck

Abstract

Background: This study presents initial data on presence of nucleostemin - a nucleolar protein typical of stem cells in the normal squamous epithelium of the oropharynx and larynx - in squamous cell carcinoma originating from these epithelia. Materials and Methods: Differentiation and proliferation markers such as keratins, β-catenin, galectin-1, and Ki-67 were studied in parallel with nucleostemin for defining cell characteristics. Results: Nucleostemin was detected in nucleoli of both proliferating basal cells and terminally differentiated suprabasal cells of normal epithelium and in tumor cells. Importantly, malignant transformation was connected with a significant enlargement of nucleostemin-positive nucleoli in these cell types. Conclusion: Detection of nucleostemin in head and neck cancer cells, together with the size of nucleoli, may be important in the evaluation of tumor differentiation and biology.