Epigenetic Alteration of the Wnt Inhibitory Factor-1 Promoter Is Common and Occurs in Advanced Stage of Tunisian Nasopharyngeal Carcinoma

Activation of the wingless-type (Wnt) signaling pathway is common in cancers. The Wnt inhibitory factor-1 (WIF-1) is a secreted antagonist that acts by binding to Wnt ligands. We examined by methylation-specific PCR (MSP), whether WIF-1 is inactivated in 68 nasopharyngeal carcinomas (NPC), and 10 normal mucosa. We showed that the WIF-1 promoter was methylated in 89.7% of tumors, whereas all normal mucosa were unmethylated. The WIF-1 methylation was associated with the tumor, node, and metastasis (TNM) (p = .003) and the age (p = .014). The Wnt-5a mRNA was higher in tumors and correlated with TNM (p = .012). The methylation of WIF-1 contributes to the activation of the Wnt pathway in NPC.