Objective: To study the significance of cytokeratin 13 (CK13) gene expression and its methylation in human nasopharyngeal carcinoma (NPC).
Methods: The expression of CK13 in 32 cases of NPC and 8 cases of chronic inflammatory diseases of nasopharyngeal epithelia (CIDNE) was studied using Northern blot hybridization. The methylation pattern of CK13 gene was analyzed by Southern blot hybridization using methylation sensitive restriction endonuclease Hpa II and Msp I in NPC cell lines HNE1 and normal human primary cultures of nasopharyngeal epithelial cells.
Results: High expression of CK13 gene was found in 8(100%) CIDNE, low-expression of the gene in 12(37.5%) NPC, negative expression in 9(28.1%) and high expression in 11(34.4%). The degree of methylation was increased in NPC cell lines HNE1, compared to that of normal human primary cultures of nasopharyngeal epithelial cells.
Conclusion: The expression of the CK13 gene in NPC is partly or completely down regulated. It is possibly related to hyper-methylation of CK13 gene.