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背景与目的:比较基因组杂交(comparativegenomichybridization,CGH)是一种在荧光原位杂交(FISH)技术上发展起来的,用于检测两个基因组间相对DNA拷贝数的改变(缺失或扩增),并将这些变化在染色体上进行定位的分子细胞遗传学方法。为全面了解鼻咽癌耐药细胞与药物敏感细胞在基因组DNA水平上可能存在的差异,以及这种差异在肿瘤耐药性产生中的意义,我们用CGH技术对鼻咽癌耐药细胞系(CNE2/DDP)和其亲代药物敏感细胞(CNE2)的基因组DNA进行检测和分析。方法:提取两种癌细胞及正常胎盘组织的基因组DNA,以随机引物法进行荧光标记(CNE2/DDP和CNE2DNA以Fluorescein-12-dUTP标记,探针显绿色荧光;正常胎盘组织以Tetramethylrhodamine-5-dUTP标记,探针显红色荧光),将标记的DNA探针同时与正常淋巴细胞分裂中期染色体进行杂交,杂交信号在荧光显微镜下经CCD(chargecoupleddevice)摄像装置摄取,并通过荧光数字图像分析系统(quipsCGHprogram)进行数据处理,计算两种荧光的比率并绘制分析图。结果:CNE2细胞存在广泛的染色体改变,主要表现在1q,3q,5p,6p,7p,8q,9q,11p,12q,19q的扩增和4q,12p,13p,14p,15p,18,20q,21p,22的缺失。从CNE2诱导的耐药细胞系CNE2/DDP恒定表现为8q,19q的扩增和8p的缺失,其它的染色体均未发现明显异常的?
BACKGROUND & AIM: Comparative genomic hybridization (CGH) is a technique developed by fluorescence in situ hybridization (FISH) to detect changes (deletions or amplifications) of relative DNA copy number between two genomes Molecular cytogenetics for locating these changes on chromosomes. In order to fully understand the differences in the genomic DNA levels of drug-resistant and drug-resistant NPC cells, and the significance of this difference in tumor drug resistance, we used CGH technology to screen NPC cell lines ( CNE2 / DDP) and its parental drug-sensitive cell (CNE2) genomic DNA for detection and analysis. Methods: The genomic DNA of two kinds of cancer cells and normal placenta tissues were extracted and labeled by random primers (Fluorescein-12-dUTP was used to label CNE2 / DDP and CNE2 DNA, and the probe showed green fluorescence. Normal placenta was labeled with Tetramethylrhodamine-5- dUTP-labeled probe, the probe was red fluorescence), the labeled DNA probe at the same time with the normal lymphocyte metaphase chromosome hybridization, hybridization signal under a fluorescence microscope CCD (CCD) camera device, and through the fluorescence digital image analysis system ( quipsCGHprogram) for data processing, calculating the ratio of the two fluorophores and plotting the analysis. Results: There was a wide range of chromosomal changes in CNE2 cells, which mainly manifested in the amplification of 1q, 3q, 5p, 6p, 7p, 8q, 9q, 11p, 12q, 19q and 4q, 12p, 13p, 14p, 15p, 18,20q, The lack of 21p, 22. The CNE2-induced cell line CNE2 / DDP consistently showed 8q, 19q amplification and 8p deletion, and no obvious abnormalities were observed in other chromosomes.