α粒子诱发BEP2D细胞癌变株中多种基因启动子的异常甲基化

Abnormal promoter methylation of multiple genes in the malignant transformed BEP2D cells induced byα-particles exposure

目的 :研究α 粒子诱发人支气管上皮细胞癌变株中 p14 ARF,p16 INK4a,MGMT ,GSTP1,BUB3和DAPK基因的甲基化情况。方法 :用甲基特异性的PCR(MSP)分析基因启动子区CpG岛的甲基化情况和用RT PCR检测细胞的基因转录水平。结果 :p14 ARF基因在BEP2D细胞中没有甲基化 ,但在其癌变细胞BERP35T1中发生了甲基化 ,且甲基化导致 p14 ARF基因的转录水平显著下降。p16 INK4a和BUB3在两种细胞中均没有发生甲基化 ,BUB3经测序证实 ;MGMT在BEP2D细胞和癌变细胞中均发生甲基化 ;DAPK在BEP2D细胞中已有部分甲基化 ,在BERP35T1细胞中完全甲基化 ;GSTP1在BEP2D细胞中没有甲基化 ,在BERP35T1细胞中发生部分甲基化。结论 :在辐射诱发人支气管上皮细胞恶性转化中 ,部分与细胞增殖。

Objective:To detect the abnormal promoter methylation of p14 ARF ,p16 INK4a ,O 6 methylguanine DNA methyltransferase (MGMT), glutathione S transferase P1 (GSTP1), BUB3 and death associated protein kinase (DAPK) genes in the transformed human bronchial epithelial cells (BEP2D) induced by α particles Methods: Abnormal promoter methylations were detected with methylation specific PCR(MSP); The level of p14 ARF gene transcription was analyzed using RT PCR Results:p14 ARF gene was not methylated in BEP2D cells, but was methylated in the malignant transformed BERP35T 1 cells, and the level of its transcription was depressed remarkably in the latter However p16 INK4a gene, which shares two exons with p14 ARF gene, was not methylated MGMT gene was methylated in both BEP2D and BERP35T 1 DAPK gene was partially methylated in BEP2D cells and methylated completely in BERP35T1 GSTP1 was not methylated in BEP2D cells and was methylated partly in BERP35T 1 BUB3 gene was not methylated in BEP2D as well as BERP35T1 cells and this was further proved by sequencing analysis Conclusion: Some of the genes which play important roles in cell proliferation, DNA repair and apoptosis were methylated in the transformed human bronchial epithelial cells induced byα particles