Abstract: To assess the expression of KLF6,p21 and c-Jun in oral squamous cell carcinoma,the expression of KLF6,p21 and c-Jun were detected by immunohistochemistry among 198 cases of cancerous tissue,49 cases of hyperplastic tissue,compared with 56 controls of normal tissue.The expression of KLF6 inthe group of normal,hyperplastic and cancerous tissue were 91.07%(51/56),83.67%(41/49),62.12%(123/198),respectively.There were significant differences amongthe three groups (P＜0.05).The positive expression of KLF6 in the group oftumor＞2 cm and moderate differentiated and poorly differentiated were significantly lower than that in the group with tumor≤2 cm and high differentiated (P＜0.01).The positive expression of p21 in cancerous tissue of 81.82%(162/198)was significantly lower than that in normal tissue with 85.71%(48/56) (P＜0.05).The expression of c-Jun in the group of normal,hyperplastic and canceroustissue were 8.93%(5/56),10.20%(5/49),46.97%(93/198),respectively.There were significant differences among the three groups (P＜0.05).The deletion or reducing of KLF6 expression in nucleus and the increasing of KLF6 expression in cytoplasm were significantly correlated with the downregulation of p21 expression in the cancerous tissues (P＜0.05).The deletion or reducing of KLF6 expression innucleus was significantly correlated with the increasing of c-Jun expression in the cancerous tissues (P＜0.01).The results indicate that the abnormal expression of KLF6,p21 and c-Jun may involve in the development of the oral squamous cell carcinoma.Further research should be done to find out the mechanism andcorrelativity.

Key words: KLF6, p21, c-Jun, oral squamous cell carcinoma