[Expression and Significance of Notch1, P21WAF1 and involucrin in nasopharyngeal carcinoma].

ABSTRACT

BACKGROUND & OBJECTIVE: Abnormal expression of Notch1 protein was often found in many kinds of primary tumors, but its correlation with nasopharyngeal carcinoma (NPC) is still unclear. This study was designed to investigate the expression of Notch1 and its downstream proteins P21(WAF1) and Involucrin in NPC, and analyze their correlations with the differentiation of NPC cells. METHODS: The expression of Notch1, P21(WAF1), and Involucrin in 101 specimens of NPC and 20 specimens of chronic inflammatory nasopharyngeal mucosa were detected by SP immunohistochemistry. RESULTS: The positive rates of Notch1, P21(WAF1), and Involucrin were 100%, 90.0%, and 100% in chronic inflammatory nasopharyngeal mucosa, and were 77.2%, 89.1%, and 80.1% in NPC, respectively. The expression of Notch1, P21(WAF1), and Involucrin were significantly suppressed along with descending differentiation of NPC (P=0.000, P=0.026, and P=0.000). The positive rates of Notch1, P21(WAF1), and Involucrin were significantly higher in keratinizing squamous cell carcinoma (KSCC) than in differentiated nonkeratinizing carcinoma (DNKC) and undifferentiated carcinoma (UDC) (P<0.05), and were significantly higher in DNKC than in UDC (P<0.05). The expression of Notch1 in NPC was positively correlated with the expression of P21(WAF1) (r=0.306, P=0.002) and Involucrin (r=0.325, P=0.001). No significant correlation was found between the expression of P21(WAF1) and Involucin. CONCLUSION: The expression of Notch1, P21(WAF1), and Involucrin are closely correlated to the differentiation of NPC cells.