Increased p50/p50 NF-κB Activation in Human Papillomavirus Type 6- or Type 11-Induced Laryngeal Papilloma Tissue

We have observed elevated NF-κB DNA-binding activity in nuclear extracts from human papillomavirus type 6- and 11-infected laryngeal papilloma tissues. The predominant DNA-binding species is the p50/p50 homodimer. The elevated NF-κB activity could be correlated with a reduced level of cytoplasmic IκBβ and could be associated with the overexpression of p21(CIP1/WAF1) in papilloma cells. Increased NF-κB activity and cytoplasmic accumulation of p21(CIP1/WAF1) might counteract death-promoting effects elicited by overexpressed PTEN and reduced activation of Akt and STAT3 previously noted in these tissues.