Reisinger Jürgen, Rumpler Silvia, Lion Thomas, Ambros Peter F
Children's Cancer Research Institute, St. Anna Kinderspital, Kinderspitalgasse 6, A-1090 Vienna, Austria.
Int J Cancer. 2006 Apr 1;118(7):1603-8. doi: 10.1002/ijc.21498.
For many Epstein-Barr virus (EBV)-associated malignancies, it is still a matter of controversy whether infected cells harbor episomal or chromosomally integrated EBV genomes or both. It is well established that the expression of EBV genes per se carries oncogenic potential, but the discrimination between episomal and integrated forms is of great relevance because integration events can contribute to the oncogenic properties of EBV, whereas host cells that exclusively harbor viral episomes may not carry the risks mediated by chromosomal integration. This notion prompted us to establish a reliable technique that not only allows to unequivocally discriminate episomal from integrated EBV DNA, but also provides detailed insights into the genomic organization of the virus. Here, we show that dynamic molecular combing of host cell DNA combined with fluorescence in situ hybridization (FISH) using EBV-specific DNA probes facilitate unambiguous discrimination of episomal from integrated viral DNA. Furthermore, the detection of highly elongated internal repeat 1 (IR1) sequences provides evidence that this method permits detection of major genomic alterations within the EBV genome. Thus, fiber FISH may also provide valuable insights into the genomic organization of viral genomes other than EBV.
对于许多与爱泼斯坦-巴尔病毒（EBV）相关的恶性肿瘤而言，受感染细胞中携带的是游离型还是染色体整合型EBV基因组，抑或是两者皆有，仍是一个存在争议的问题。EBV基因本身的表达具有致癌潜力，这一点已得到充分证实，但区分游离型和整合型形式具有重要意义，因为整合事件可能会促成EBV的致癌特性，而仅携带病毒游离体的宿主细胞可能不会承担由染色体整合介导的风险。这一观点促使我们建立一种可靠的技术，该技术不仅能够明确区分游离型与整合型EBV DNA，还能深入了解病毒的基因组组织。在此，我们表明，宿主细胞DNA的动态分子梳技术结合使用EBV特异性DNA探针的荧光原位杂交（FISH），有助于明确区分游离型与整合型病毒DNA。此外，对高度拉长的内部重复序列1（IR1）的检测提供了证据，证明该方法能够检测EBV基因组内的主要基因组改变。因此，纤维FISH也可能为除EBV之外的其他病毒基因组的组织提供有价值的见解。
