Expression of Cell Cycle-Related Proteins p16, p27, p53 and Ki-67 in HPV-positive and -negative Samples of Papillomas of the Upper Respiratory Tract

Background: The role of human papillomavirus (HPV) infection as an etiological factor of respiratory tract papillomas has been described in numerous studies, however its role in malignant transformation has not been clearly defined. Depending on their oncogenic potential they have been classified as low- and high-risk HPVs. We analyzed the expression of four cell cycle-related proteins in order to understand the processes leading to malignant transformation. Materials and Methods: Fifty-six cases of pharyngeal and laryngeal papillomas were analyzed. Nested multiplex polymerase chain reactions to detect the presence of the HPV types, as well as immunohistochemical reactions were performed for the detection of cell cycle-related proteins p16, p27, p53 and Ki-67. Results: The presence of HPVs 6/11 and 16 was confirmed in 10/56 cases. The expression of all analyzed cell cycle-related proteins was increased in HPV-infected papillomas. Conclusion: HPV infection of the upper respiratory tract may influence the expression of cell cycle-related proteins, that could indicate its possible role in the process of malignant transformation.