Objective To study the expression and significance of p65 which is an important subtype of nuclear transcription factorκB (NF-κB) and its inhibitory protein IκBαin malignant transformation of hamster buccal mucosa.Methods The animal model of malignant transformation in hamster buccal mucosa induced by DMBA(0.5%) was established. Twelve paired specimens including normal buccal mucosa, epithelial hyperplasia, epithelial dysplasia and squamous cell carcinoma (SCC) were subjected to Western blot for the analysis of p65.The expression of IκBαwas observed in 22 normal buccal epithelia, 20 hyperplasia epithelia, 35 dysplasia epithelia and 23 SCC by immunohistochemical evaluation.Results In normal buccal epithelia and hyperplasia ep- ithelia, the expression of p65 was not obvious, and there was no significant difference between them(P>0.05).The expression of IκBαexisted at large, but mostly localizing in cell cytoplasmic staining in the basal cell layer and bottom of spinocelluar layer. With the occurrence of epithelia dysplasia,the expression of p65 gradually increased,comparing with normal buccal epithelia and hyperplasia epithelia(P
