非小细胞肺癌RASSF1A基因甲基化及下游基因表达

Analysis of Methylation Status of RASSF1A promoter Region and Transcription Level of Downstream Genes in Non-Small Cell Lung Cancer

目的:研究非小细胞肺癌RASSF1A基因启动子甲基化及下游基因表达情况。方法:留取58例非小细胞肺癌患者手术标本及正常肺组织,甲基化特异性PCR分析RASSF1A基因启动子甲基化情况,同时Northern blot分析SM22、SPARC、SDHB和CC- ND3等4种RASSF1A下游基因的表达情况。结果:58例非小细胞肺癌中RASSF1A基因启动子甲基化阳性率为34．5％,甲基化与各临床参数之间无显著相关性,SM22和SPARC在RASSF1A甲基化组表达明显下调。结论:原发性非小细胞肺癌中存在着较高比例的RASSF1A启动子过度甲基化,并与下游基因SM22和SPARC的表达下调密切相关,提示RASSF1A在非小细胞肺癌的发生中起着多种作用。

Objective： To investigate the methylation status of RASSF1A promoter region and transcription level of downstream genes in non-small cell lung cancer （NSCLC）. Methods： 58 resected non-small call lung cancer and corresponding normal lung tissue sample were collected. Methylation specific PCR was conducted to determine the methylation status of RASSF1A promoter, and Northern blot analysis was conducted to detect the transcription levels of SM22, SPARC, SDHB and CCNDo Results： Among 58 NSCLC samples,the positive rate of methylation of RASSF1A promoter was 34.5%（n=20）; there was no significant corrdation between the methylation status and clinical parameters. Transcription levels of SM22 and SPARC were significantly down-regulated in RASSF1A methylated cases, Conclusion： Frequent hypermethylation of RASSF1A promoter exists in primary non-small cell lung cancer, which is associated with the down-regulation of downstream gene SM22 and SPARC, so it is suggested that RASSF1A plays a multifunctional role in the genesis of non-small cell lung cancer.