STRUCTURE AND ORGANIZATION OF AMPLIFIED DNA ON DOUBLE MINUTES CONTAINING THE MDM2 ONCOGENE
STRUCTURE AND ORGANIZATION OF AMPLIFIED DNA ON DOUBLE MINUTES CONTAINING THE MDM2 ONCOGENE
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DOI：
10.1006/geno.1993.1058
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发表时间：
1993-02-01
期刊：
影响因子：
4.4
通讯作者：
GEORGE, DL
中科院分区：
文献类型：
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作者：
FAKHARZADEH, SS;ROSENBLUMVOS, L;GEORGE, DL
我们一直在研究小鼠成纤维细胞系 (3T3DM) 的转化衍生物，它能稳定维持双微小染色体 (DM)。在本报告中，我们描述了对该细胞系内 DM 结构的全面分析，综合利用脉冲场凝胶电泳的长程作图、筛选富含 DM 的基因组文库以及使用轮廓钳均质电场 (CHEF) 凝胶电泳确定 DM 大小。我们的数据表明，这些细胞中的微小颗粒以均匀的圆形分子群存在，大小约为 4 Mb，三个基因在其上扩增。其中之一是 dm2 癌基因，该基因也被发现在许多人类肉瘤中被扩增。此外，我们提供的证据表明，这三个基因排列为两个相同的反向重复单元，通过异质大小的间隔区连接。这项工作产生了第一个包含扩增癌基因的完整双微小粒子结构的模型；该模型为肿瘤细胞基因扩增过程中发生的后续事件提供了线索。
We have been studying a transformed derivative of a mouse fibroblast line (3T3DM) that stably maintains double minute chromosomes (DMs). In this report we describe a comprehensive analysis of the structure of the DMs within this cell line, utilizing a combination of long-range mapping via pulsed-field gel electrophoresis, screening of DM-enriched genomic libraries, and DM sizing using contour-clamped homogeneous electric field (CHEF) gel electrophoresis. Our data indicate that the minute particles in these cells exist as a homogeneous population of circular molecules, roughly 4 Mb in size, upon which three genes are amplified. One of these is themdm2oncogene, which has also been found to be amplified in a number of human sarcomas. Further, we present evidence that these three genes are arranged as two identical inverted repeat units linked by spacer regions of heterogeneous size. This work has led to the first model for the structure of an entire double minute particle containing an amplified oncogene; this model provides clues to later events occurring in the gene amplification process in tumor cells.