鼻咽癌中PCDH17基因启动子甲基化状态的研究

Methylation status of the PCDH17 gene promoter in Nasopharyngeal carcinoma

摘要:

目的：探讨鼻咽癌（Nasopharyngeal carcinoma，NPC）细胞株中PCDH17基因启动子区甲基化状态及其对转录表达的影响。探讨PCDH17在NPC中发挥的功能。方法：运用半定量反转录PCR和甲基化特异性PCR（Methylation-specific PCR，MSP）检测5株NPC细胞株，人喉鳞癌细胞株（Fadu），正常鼻咽上皮永生细胞系（NP69）中PCDH17mRNA的表达情况及PCDH17的甲基化情况。去甲基化药物处理细胞株后PCDH17的表达及甲基化的变化。应用细胞克隆形成实验及划痕实验检测PCDH17在NPC中的功能。结果：5株NPC细胞株中无PCDH17mRNA表达，Fadu中无表达，NP69有表达。去甲基化药物处理细胞株后PCDH17mRNA表达上调。细胞功能实验提示PCDH17可以抑制细胞克隆形成及迁移。结论：NPC细胞株中PCDH17mRNA表达下调主要受甲基化调控，PCDH17在NPC中发挥着抑癌基因的作用。

Abstract:

Objective：To investigate PCDH17 gene promoter methylation status and its impact on the transcriptional expression of PCDH17 in NPC （Nasopharyngeal carcinoma，NPC） cell lines.and to investigate the function of PCDH17 in nasopharyngeal carcino－ma. Methods：Semi-quantitative reverse transcription PCR （RT-PCR） and Methylation specific PCR（MSP） were used not only to de－tect transcription level and promoter methylation status of PCDH17 gene in five NPC cell lines，human laryngeal carcinoma cell line （Fadu），normal immortalized epithelial cell lines（NP69），but also after NPC cell lines were exposed to demethylating agent.The tu－mor-suppressive function of PCDH17 in NPC cancer was investigated further in vitro assays. Results：PCDH17 was not expressed in 5 NPC cell lines and in Fadu，but expressed in NP69.Demethylating agent could restore the expression of PCDH17 mRNA.The Cell function experiments suggest that PCDH17 could inhibit the cell colony formation and migration. Conclusion：The transcriptional in－activation in NPC cell lines is mainly caused by the DNA methylation.PCDH17 plays a role of tumor suppressor gene in NPC.