EXPRESSION OF P16 GENE IN ORAL SQUAMOUS CELL CARCINOMA AND ITS CLINICOPATHOLOGICAL SIGNIFICANCE

Objective To study the expression of p16 gene in oral squamous cell carcinoma and its clinicopathological meaning. Methods 48 patients with oral squamous cell carcinoma and 6 normal oral mucosa were included in this study; In situ hybridization was used to investigate distribution and intensity of p16 mRNA in cancer and normal tissue, expression of p16 was detected by Western blotting; The relationship between p16 protein expression and location, differentiation and clinical stage was analyzed using x 2 test. Results p16 mRNA expression was all positive in 6 normal mucous tissue; 21 of 48 (43.7%) cases with oral squamous cell carcinoma were found to have negative expression of p16 mRNA, the hybridization signal located in plasm of cancer cells; Western blotting showed that 26 cases had no p16 protein, 21 patients with no mRNA signal were all found no p16 protein expression, however, the rest 5 cases without p16 protein could be seen to have mRNA hybridization signal in cancer cells; Statistical analysis showed that p16 protein expression had no correlation with location, differentiation and clinical stage of oral squamous cell carcinoma, but significant relationship was found between p16 protein expression and metastases of cancer to neck lymph nodes ( P 0.01). Conclusion Lose of p16 gene product is a common event in development of oral squamous cell carcinoma and probably affect the metastatic characters of cancer cells.