The nuclear localization of NFκB and p53 is positively correlated with HPV16 E7 level in laryngeal squamous cell carcinoma

Abstract

The interaction between the HPV (human papilloma virus) 16 E7 and other cell growth factors, such as p53 and NFκB in laryngeal cancer is not clearly understood. The aim of this study was to examine the expression of these three proteins in tumor and nontumor laryngeal tissues from patients with laryngeal squamous cell carcinoma. These three proteins were dominantly expressed in the nucleus and their levels were higher in the tumor tissue than in the non-tumor tissue, although the comparison between the tumor and non-tumor tissues of p53 staining did not reach significance. The intensity of the nuclear stain of E7 and p53 was stronger than that of p65, a subunit of NFκB. Correlation analysis revealed that there was a positive relationship between the level of HPV16 E7 and the expression of p65. The correlation between E7 and p53 was also significant, although to a lesser degree. The finding of nuclear localization of p65 suggests that NFκB is constantly activated in the laryngeal cancer cells, whereas the sequestration of p53 in the nucleus may represent a mutated form of p53, which is probably inactivated by HPV16 oncoproteins. In conclusion, this study suggests that the nuclear localization of NFκB and p53 may play a role in the development of human laryngeal squamous cell carcinoma infected with HPV16.