支气管上皮细胞辐射致癌模型中MTAP表达的调控方式研究  

Downregulation of MTAP gene in malignanant bronchial epithelial cells irradiated by α particles caused by LOH

作　　者：李邦印[1] 张开泰[2] 霍艳英[1] 胡迎春[1] 徐勤枝[1] 周平坤[1] 吴德昌[2] 

机构地区：[1]军事医学科学院辐射与放射医学研究所,北京100850 [2]解放军总医院第二附属医院,北京北京100091

出　　处：《临床肺科杂志》2007年第7期673-675,共3页Journal of Clinical Pulmonary Medicine

基　　金：国家重点基础研究发展规划973项目(批准号G1998051207)基金资助

摘　　要：目的从基因组水平探讨BEP2D辐射致癌模型中MTAP基因表达降低的原因。方法培养和传代BEP2D和BERP35T-2细胞,提取基因组DNA;设计针对MTAP基因8个外显子的引物,PCR扩增方式观察MTAP有无纯合性缺失,并对PCR产物进行SSCP分析;选择9p21.3区的三个STS位点,PCR扩增分析该区域杂合性缺失的状况;设计针对MTAP基因CpG岛的MSP(Methylation-specified PCR甲基化特异性)引物,对基因组DNA进行硫化处理和纯化,PCR扩增以研究MTAP基因区域的杂合性缺失现象。结果在细胞中MTAP基因没有发生纯合性缺失和点突变,启动子区域亦没有甲基化调节现象;BERP35T-2细胞有杂合型缺失(Loss of Heterodeletion,LOH)现象,发生位置在RH99034。结论在致癌模型中MTAP基因的表达降低或丧失是因为MTAP所在的基因组区域发生了杂合性缺失,提示9p21.3区域的杂合性缺失可能是肺癌中发生的高频率事件。Objective The reasons of expressing alteration of MTAP gene was investigated in tumorgenesis of bronchial epithelial cell line irradiated by a single dose of high-energy α particles. Methods BEP2D and BERP35T-2 cells was cultured and collected. The genomic DNA was then extracted. Primers for MTAP exons were designed. By PCR amplification, homodeletion and mutations of MTAP gene were analyzed. The methylation of promoter of MTAP gene was analyzed by MSP （ Methylation-specific PCR）. Three STSs, D9S171, D9S162 and RH99034, flanking MTAP gene region, were analyzed by PCR amplification. Result In BERP35T-2,No mutations and homodeletions were found in MTAP exons, and no methylations took place in the CpG island of MTAP promoter. LOH was found in BERP35T-2 at STS RH99034, which was located between D9S171 and D9S162. Conclusion The results have indicated that LOH at RH99034 which takes place inevitably in BERP35T-2 cell line may contribute to the elevating malignancy of BERF35T -2. LOH at 9p21. 3 might be high -frequent incidents occurred in lung cancers.

关 键 词：BEP2D 杂合性缺失 MTAP 

分 类 号：R73-3[医药卫生—肿瘤]