An Anti-apoptotic Role of NF-κB in TNFα-induced Apoptosis in an Ameloblastoma Cell Line

Nuclear factor-κB (NF-κB) is involved in the promotion of cell survival in a variety of cell types. The present study focused on the role of NF-κB in TNFα-induced apoptosis in an ameloblastoma. Immunohistochemical staining revealed p65 NF-κB protein to be expressed in ameloblastoma tissues. Furthermore, immunoblotting and immunocytochemistry analyses showed that the stimulation of TNFα in an ameloblastoma cell line (AM-1) induced p65 NF-κB translocation from the cytoplasm to the nucleus, indicating NF-κB activation. These findings were confirmed by an NF-κB luciferase reporter assay, which detected enhanced NF-κB transcription activity of AM-1 cells by TNFα stimulation. Moreover, pretreatment with SN50, a nuclear translocation inhibitor, prior to TNFα stimulation, effectively inhibited TNFα-induced NF-κB activation in AM-1 cells. In order to reveal the role of NF-κB activation during TNFα-induced apoptosis in AM-1 cells, an apoptosis assay was performed, and showed that the potential of TNFα in inducing apoptosis in AM-1 cells was significantly elevated by inhibiting the NF-κB activation. These results suggest that NF-κB plays an anti-apoptotic role in TNFα-induced apoptosis in AM-1 cells.