INTEGRATION OF HUMAN PAPILLOMAVIRUS TYPE-16 INTO THE HUMAN GENOME CORRELATES WITH A SELECTIVE GROWTH ADVANTAGE OF CELLS
INTEGRATION OF HUMAN PAPILLOMAVIRUS TYPE-16 INTO THE HUMAN GENOME CORRELATES WITH A SELECTIVE GROWTH ADVANTAGE OF CELLS
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DOI：
10.1128/jvi.69.5.2989-2997.1995
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发表时间：
1995-05-01
影响因子：
5.4
通讯作者：
LAMBERT, PF
中科院分区：
文献类型：
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作者：
JEON, S;ALLENHOFFMANN, BL;LAMBERT, PF
人乳头瘤病毒16型（HPV-16）DNA整合到宿主染色体中已被假设导致宫颈癌中两种病毒转化基因E6和E7的表达改变。为了研究病毒基因组状态和基因表达的变化在宫颈癌发生中的作用，我们推导了人类宫颈上皮细胞的克隆群体，这些细胞含有多个染色体外或整合的病毒DNA拷贝。携带染色体外HPV-16 DNA的克隆群体在至少15次传代中稳定地维持约1，000个病毒拷贝（类似于100个细胞倍增），这与亲本对应物中不稳定的HPV-16复制子形成对比。在携带整合的病毒DNA的克隆群体中，发现3至60个拷贝的HPV-16 DNA以两种形式整合：1型，其中在整合时所有HPV-16 DNA拷贝在E2开放阅读框中被破坏，2型，其中完整的病毒拷贝被破坏的病毒拷贝和细胞序列储存。尽管HPV-16 DNA拷贝数较低，但具有整合的病毒DNA的克隆群体的E7蛋白水平在大多数情况下高于在携带染色体外病毒DNA的克隆群体中发现的水平。无论病毒基因组状态如何，克隆群体都能够进行终末分化，并且不能在软琼脂中形成集落，这表明这些细胞具有非致瘤性。重要的是，当这些细胞共培养一段时间后，发现具有整合的病毒DNA的细胞群比具有染色体外DNA的细胞群生长得更快。因此，人乳头瘤病毒DNA的整合与增加的病毒基因表达和细胞生长优势相关。这些观察结果是一致的假设，即整合提供了一个选择性的优势，宫颈癌的宫颈上皮前体。
Integration of human papillomavirus type 16 (HPV-16) DNA into a host chromosome has been hypothesized to result in altered expression of two viral transforming genes, E6 and E7, in cervical cancers. In order to investigate the role that changes in viral genomic state and gene expression play in cervical carcinogenesis, we have derived clonal populations of human cervical epithelial cells which harbor multiple copies of either extrachromosomal or integrated viral DNA. The clonal populations harboring extrachromosomal HPV-16 DNA stably maintained approximately 1,000 viral copies for at least 15 passages (similar to 100 cell doublings), which contrasted with the unstable HPV-16 replicons in the parental counterpart. In the clonal populations harboring integrated viral DNA, 3 to 60 copies of HPV-16 DNA were found integrated in either of two forms: type 1, in which all the copies of HPV-16 DNA were disrupted in the E2 open reading frame upon integration, and type 2, in which intact viral copies were banked by disrupted viral copies and cellular sequences. Despite the lower HPV-16 DNA copy number, the clonal populations with integrated viral DNA had levels of E7 protein that were in most cases higher than those found in the clonal populations harboring extrachromosomal viral DNA. Irrespective of viral genomic state, the clonal populations were capable of undergoing terminal differentiation and unable to form colonies in soft agar, which is indicative of the nontumorigenic nature of these cells. Importantly, a cell population with integrated viral DNA was found to outgrow another with extrachromosomal DNA when these cells were cocultured over a period of time. Thus, integration of human papillomaviral DNA correlates with increased viral gene expression and cellular growth advantage. These observations are consistent with the hypothesis that integration provides a selective advantage to cervical epithelial precursors of cervical carcinoma.