Both conserved region 1 (CR1) and CR2 of the human papillomavirus type 16 E7 oncogene are required for induction of epidermal hyperplasia and tumor formation in transgenic mice
Both conserved region 1 (CR1) and CR2 of the human papillomavirus type 16 E7 oncogene are required for induction of epidermal hyperplasia and tumor formation in transgenic mice
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DOI：
10.1128/jvi.71.8.5905-5914.1997
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发表时间：
1997-08-01
影响因子：
5.4
通讯作者：
Lambert, PF
中科院分区：
文献类型：
--
作者：
Gulliver, GA;Herber, RL;Lambert, PF
高危型人乳头瘤病毒16型（HPV-16）和HPV-18与大多数人宫颈癌相关，并且通常发现两种病毒基因HPV E6和E7在这些癌症中表达。HPV-16 E7的存在足以在转基因小鼠中诱导表皮增生和上皮肿瘤。在这项研究中，我们进行了实验，在转基因小鼠，以确定哪些领域的E7有助于这些在体内的属性。人角蛋白14启动子用于指导突变型E7基因在小鼠复层鳞状上皮中的表达。选择的E7突变体在保守区2（CR2）结构域中具有框内缺失，这是视网膜母细胞瘤肿瘤抑制蛋白（pRb）和pRb样蛋白结合所需的，或者在E7 CR 1结构域中具有框内缺失。CR 1结构域在除pRb结合以外的水平上促进细胞转化。产生了四个具有CR 1缺失的HPV-16 E7转基因动物系和五个具有CR2缺失的转基因动物系，并观察了明显的组织学表型。进行了详细的时间过程分析，以监测野生型与突变体E7对表皮（高水平表达的位点）的急性效应。在转基因小鼠中，野生型E7基因的HPV-16 E7的年龄依赖性表达与表皮增生的严重程度相关。类似的年龄依赖性模式的突变E7基因的表达未能导致任何表型。此外，带有突变E7基因的转基因小鼠没有发生肿瘤。这些实验表明，通过CR2结构域的E7的pRb和pRb样蛋白的结合和失活是必要的诱导表皮增生和癌变的小鼠胫骨，也表明了CRI结构域在诱导这些表型的作用，通过尚未确定的机制。
High-risk human papillomavirus type 16 (HPV-16) and HPV-18 are associated with the majority of human cervical carcinomas, and two viral genes, HPV E6 and E7, are commonly found to be expressed in these cancers. The presence of HPV-16 E7 is sufficient to induce epidermal hyperplasia and epithelial tumors in transgenic mice. In this study, we have performed experiments in transgenic mice to determine which domains of E7 contribute to these in vivo properties. The human keratin 14 promoter was used to direct expression of mutant E7 genes to stratified squamous epithelia in mice. The E7 mutants chosen had either an in-frame deletion in the conserved region 2 (CR2) domain, which is required for binding of the retinoblastoma tumor suppressor protein (pRb) and pRb-like proteins, or an in-frame deletion in the E7 CR1 domain. The CR1 domain contributes to cellular transformation at a level other than pRb binding. Four lines of animals transgenic for an HPV-16 E7 harboring a CR1 deletion and five lines harboring a CR2 deletion were generated and were observed for overt and histological phenotypes. A detailed time course analysis was performed to monitor acute effects of wild-type versus mutant E7 on the epidermis, a site of high-level expression. In the transgenic mice ,vith the wild-type E7 gene, age-dependent expression of HPV-16 E7 correlated with the severity of epidermal hyperplasia. Similar age-dependent patterns of expression of the mutant E7 genes failed to result in any phenotypes. In addition, the transgenic mice with a mutant E7 gene did not develop tumors. These experiments indicate that binding and inactivation of pRb and pRb-like proteins through the CR2 domain of E7 are necessary for induction of epidermal hyperplasia and carcinogenesis in mouse shin and also suggest a role for the CRI domain in the induction of these phenotypes through as-yet-uncharacterized mechanisms.