Expression of NF-κB and IL-6 in oral precancerous and cancerous lesions: an immunohistochemical study

摘要

Background: The purpose of this study was to evaluate the immunohistochemical expression of NF-κB andIL-6 in oral premalignant and malignant lesions and to investigate their possible correlation with the presence ofsubepithelial inflammation.Material and Methods: Thirty two oral premalignant lesions, clinically compatible with leukoplakia orerythroplakia, were investigated. Microscopically, 11 of them showed hyperkeratosis and acanthosis (epithelialhyperplasia) and 21 showed dysplasia of varying degrees. Nine cases of OSCC and four control cases of normaloral mucosa were also included in the study. Immunohistochemical staining with NF-κB (p65) and IL-6 wasperformed. IL-6 and nuclear NF-κB staining were assessed as positive or negative. For cytoplasmic localizationof NF-κB, a total score combining intensity and percentage of positive epithelial cells was additionally calculated.The presence of inflammation was also recorded.Results: Intensity and total scores for NF-κΒ cytoplasmic immunostaining showed a statistically significantgradual increase from normal mucosa to OSCC (p=0.012 and p=0.026 respectively). Non-statistically significantincreased NF-κΒ nuclear localization was detected in dysplasias and OSCCs. Positive statistical correlation wasdetected between the presence of inflammation and IL-6 expression (p=0.015). No correlation between NF-κΒand IL-6 was detected.Conclusions: NF-κΒ is activated in the early stages of oral carcinogenesis. IL-6 may have an NF-κΒ-independentrole, possibly through regulation of the inflammatory response.