Aberrant promoter methylation reduced the expression of protocadherin 17 in nasopharyngeal cancer

Objective: This study aimed to explore the underlying mechanism of protocadherin 17 (PCDH17) downregulated in nasopharyngeal cancer (NPC). Methods: NPC tumor and adjacent tissue samples were collected from NPC patients who were received therapy in Chinese PLA General Hospital. Meanwhile, a normal epithelial cell lines NP96 and 6 NPC cell lines C666-1, CEN1, CEN2, HNE1, HEN2, and HONE1 were prepared. Then, the expression level of PCDH17 and the methylation level of PCDH17 promoter in both tissues samples and cell lines were determined using PCR method. Moreover, PCDH17 was overexpressed in CNE2 and HONE1 using Lipo2000. Following this, the proliferation and apoptosis of CNE2 and HONE1 were assessed using MTT and flow cytometry. Results: The expression of PCDH17 was significantly downregulated in NPC tissues compared with the adjacent tissues, as well as in the NPC cell lines compared the normal NP96 cells. Overexpressed PCDH17 could significantly inhibited the proliferation of CNE2 and HONE1 cells, but obv...