Abstract: Objective To explore the expression and clinical significance of cellular inhibitor of apoptosis protein 2 (c-IAP2) in nasopharyngeal carcinoma (NPC). Methods The NPC tissues and the nasopharyngeal normal tissues were obtained from 95 NPC patients and 40 non-NPC patients, respectively, and their clinico-prognostical data were analyzed. The expression of c-IAP2 mRNA and protein in these tissues was detected by RT-PCR, immunochemistry and Western blotting, respectively. The relationship between the clinicopathological characteristics and c-IAP2 expression was analyzed by the chi-square test. Kaplan-Meier combined with Log-rank was used to test the survival difference of patients with different expression levels of c-IAP2. Moreover, univariate and multivariate Cox proportional risk regression models were used to analyze the risk factors affecting the prognosis of NPC patients. Results RT-PCR showed that the mRNA expression level of cIAP2 was significantly increased in NPC tissues when compared with normal tissues (t =12. 62, P< 0. 001). Western blotting analysis showed that the expression level of c-IAP2 protein was significantly up-regulated in NPC tissues, which was consistent with the change of c-IAP2 mRNA expression level. Furthermore, the immunohistochemical analysis displayed that c-IAP2 was highly expressed in NPC tissues, and its expression level was associated with tumor differentiation, T staging, N staging, and TNM staging (P < 0. 05, respectively). Survival analysis found that the overall survival rate in NPC patients with low c-IAP2 expression level was significantly higher than that in NPC patients with high c-IAP2 expression level (χ 2 = 11. 86, P = 0. 001), and the high expression of cIAP2 was an independent risk factor for shortened overall survival of patients with NPC ( HR = 2. 425, 95% CI: 1. 256 ~ 4. 994, P = 0. 012). Conclusion The expression level of c-IAP2 in NPC is significantly up-regulated, and its high expression is significantly correlated with the poor prognosis of NPC patients, which has potential clinical value for evaluating the prognosis of patients with NPC.

Key words: nasopharyngeal carcinoma, c-IAP2, clinicopathological characteristics, prognosis