原钙黏蛋白-20在肺癌组织中表达及其机制

Expression and potential mechanism of protocadherins 10 in lung cancer tissues

目的 探讨原钙黏蛋白-20 （PCDH20）的表达与其启动子区甲基化水平的关系以及PCDH20基因在肺癌发生、发展中的作用及相关的作用机制.方法 采用半定量逆转录-聚合酶链反应（SqRT-PCR）检测PCDH20在15例正常成人肺组织和20例肺癌组织的表达;用甲基化特异性PCR（MSP）检测20例肺癌组织中PCDH20启动子区的甲基化水平.结果 PCDH20在几乎所有正常组织中表达,在95％的肺癌组织中不表达（19/20）.80％的肺癌组织中存在PCDH20启动子的甲基化,而在正常肺组织中未检测到.结论 DNA甲基化是PCDH20在肺癌中表达下调或缺失的原因之一,PCDH20在大肠癌的发生发展中起抑制作用.

Objective To explore the function and potential mechanism of protocadherin 20 （PCDH20） gene in lung cancer development.Methods Expression of PCDH20 was detected in 15 cases of normal adult tissues and 20 cases of lung cancer by semi-quantitative reverse transcription-polymerase chain reaction （SqRT-PCR）,and the level of PCDH20 promoter methylation in lung cancer and normal tissues was evaluated by methylation-specific PCR （MSP）.Results PCDH20 was expressed in all normal adult tissues but low or silenced in 95％ （19/20） lung cancer tissue.Methylation of the CpG-rich promoter region of PCDH20 was detected in 80％ （12/15） lung tumors,which was significantly different from the status in normal lung tissues （P ＜ 0.01）.Conclusion These results suggest that epigenetic silencing of PCDH20 is common in lung cancer,and PCDH20 acts as a tumor suppressor in the carcinogenesis.