Expression of p16, nm23-H1, E-cadherin, and CD44 gene products and their significance in nasopharyngeal carcinoma

OBJECTIVE: The present study was aimed to determine whether p16/MTS1, nm23-H1, E-cadherin, and CD44 proteins were expressed in nasopharyngeal carcinoma (NPC) and whether those expressions were pathologically significant in the progress of NPC. METHOD: We examined non-cancerous nasopharyngeal mucosa (20 cases) and NPC (80 cases) using immunohistochemistry with six different types of monoclonal antibodies against p16, nm23-H1, E-cadherin, CD44H, CD44v3, and CD44v6 proteins. RESULTS: The results showed that 1) the rates of positive p16 protein expression and of preserved E-cadherin protein expression in NPC were significantly lower than those in non-cancerous tissue (P <.01); 2) no significant difference in the rate of positive expression of nm23-H1, CD44H, CD44v3, and CD44v6 proteins were observed between non-cancerous nasopharyngeal mucosa and NPC; 3) no significant difference in the expression of those proteins were found by respective correlation analyses of sex, stage, and size of primary tumor in NPC; and 4) no significant difference in the rates of positive expression of CD44H, CD44v3, and CD44v6 proteins were observed in NPC between with and without lymph node metastasis, indicating that those gene products did not correlate with lymph node metastasis in NPC. However, there were inverse correlations between the expression of p16, nm23-H1, or E-cadherin protein and lymph node metastasis (P <.05), indicating that the expression of p16, nm23-H1, and E-cadherin gene were related to the carcinogenesis and tumor progression of NPC. CONCLUSION: Detecting the expressions of those gene products may provide clinically valuable information for therapeutic strategy and for predicting the prognosis of patients with NPC.