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, beta-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.

Institute of Anatomy and Head and Neck Surgery 1st Faculty of Medicine 2nd Faculty of Medicine Charles University Prague Czech Republic

Regulatory T cells and their prognostic value for patients with squamous cell carcinoma of the head and neck