【摘要】 目的　对 3株肺癌细胞中 9个肿瘤相关基因的启动子甲基化状态和部分基因表达的相关性进行评估。方法　通过甲基化特异性多聚酶链反应法 (MSP)结合DNA测序来确定 3株肺腺癌细胞株 (A5 4 9,SH77和SPE A 1)中 9个基因的启动子CpG岛的甲基化状态 :APC ,CDH13,DAPK1,MGMT ,MYOD1,p16 INK4a,p73,RAR β和WT1基因。同时采用半定量RT PCR的方法来量度下列 5个基因的表达 :CDH13,MGMT ,MYOD1,RAR β和WT1基因。结果　在 9个受检基因之中 ,下列 4个基因在三株细胞中均呈同样的甲基化谱式 :仅有去甲基化 :APC和DAPK1,以及兼有甲基化和去甲基化 :p73和p16 INK4a。而其余 5个基因则表现为不同的甲基化模式。尽管 ,这 5个基因的表达谱式大体上符合其启动子CpG岛甲基化的表达静息的原则 ,个别的例外亦是有的。这提示着与DNA甲基化状态无关的机制可能也会参与该基因的表达调控。结论　肺癌细胞株中的肿瘤相关基因的启动子CpG岛的过甲基化可与该基因的表达状态有较高的相关性更多还原

【Abstract】 Objective To correlate the methylation status of the promoter CpG islands of nine genes with their expressions in lung cancer cells. Methods: This paper used methylation specific PCR method (MSP) in conjunction with DNA sequencing to methylation profiles of the promoter CpG islands of the following nine genes, APC, CDH13, DAPK1, MGMT, MYOD1, p16 INK4a , p73, RAR β and WT1, the methylation patterns of which were altered significantly in three lung cancer cell lines, A549, SH77 and SPC A 1. It also used the semi quantitative RT PCR method to assess the expression of the following five genes: CDH13, MGMT, MYOD1, RAR β and WT1. Results: The following four genes displayed the uniform methylation status: 1) either APC and DAPK1 were unmethylated; 2) p16 INK4a and p73 were co existed unmethylated and methylated. Semi quantitative PCR analyses of the rest five genes that varied in methylation pattern among three lung cancer cell lines supported the general notion that the hypermethylated status of the promoter CpG islands of the genes represents the silenced state of gene transcription. However, there were several exceptions, indicating that other mechanisms may underlie the changed patterns of expression of the relevant genes observed. Discussion: The methylation status of the promoter CpG islands of the tumor associated genes indeed reflects the transcription status of the genes in majority of cases as revealed in the report.更多还原