Project 4: Regulation of EBV Latency and Oncogenesis by Hypoxia

摘要： 爱泼斯坦-巴尔病毒(EBV)是一种人类伽马疱疹病毒，与多种淋巴和上皮细胞有关 恶性肿瘤。像所有癌症一样，EBV相关癌症必须在营养耗尽的情况下竞争和生存。 环境。对氧气波动的适应是大多数癌症的标志。在这个提案中，我们调查了 氧代谢如何在EBV潜伏期和肿瘤发生中发挥核心作用。对于目标1，我们将调查 EBV在初次感染过程中如何调节宿主的缺氧反应。我们的初步数据显示EBNA1 EBNA2可以结合和调节控制低氧反应的细胞基因，包括可诱导的低氧 因子1α(HIF1a)。我们将检验EBV感染调节宿主对缺氧反应的假设 以促进感染细胞存活并促进肿瘤的形成。对于目标2，我们将调查病毒是如何 表观基因组受氧感受酶的调控。EB病毒相关性Burkitt淋巴瘤与上皮性 众所周知，恶性肿瘤会获得高DNA甲基化，通常被称为CpG岛甲基化 表型(CIMP)。我们将研究DNA甲基化是如何通过氧敏感控制来调节的 并探索低氧如何导致CIMP和肿瘤抑制基因的沉默。为 目的3，我们将测试氧气感受酶如何在潜伏期调节EBNA1和EBV Episome的维持。 我们发现，脯氨酸和赖氨酸羟化酶调节EBNA1和EBNA2蛋白的稳定性和功能。 我们已经定位了EBNA1上与赖氨酸羟基酶PLOD1结合的相互作用位点，并发现了这种相互作用 对于EBNA1蛋白在常压下的稳定性是必不可少的。我们现在建议研究低氧是如何调节细胞内 PLOD1与EBNA1相互作用控制EBV潜伏感染期间EB病毒的维持和持续。 这些目标与探索相关低氧影响的计划项目的其他成员高度整合 肿瘤病毒。总之，这些目标将提供一个框架，以了解病毒如何对缺氧做出反应 促进宿主细胞存活并驱动致癌过程。

Abstract: Epstein-Barr Virus (EBV) a human gammaherpesvirus that is associated with diverse lymphoid and epithelial malignancies. Like all cancers, EBV-associated cancers must compete and survive in nutrient depleted environments. Adaptation to oxygen fluctuation is a hallmark of most cancers. In this proposal, we investigate how oxygen metabolism plays a central role in EBV latency and tumorigenesis. For aim 1, we will investigate how EBV modulates the host hypoxic response during primary infection. Our preliminary data indicates EBNA1 and EBNA2 can bind and regulate cellular genes controlling the hypoxic response, including hypoxia inducible factor 1 alpha (HIF1A). We will test the hypothesis that EBV infection modulates the host response to hypoxia to promote infected cell survival and promote tumorigenesis. For aim 2, we will investigate how the viral epigenome is regulated by oxygen sensing enzymes. EBV associated Burkitt lymphoma (BL) and epithelial malignancies are known to acquire high DNA methylation commonly referred to as the CpG island methylator phenotype (CIMP). We will investigate how DNA methylation is regulated through the oxygen-sensitive control of TET2 enzymes and explore how hypoxia contributes to CIMP and silencing of tumor suppressor genes. For aim 3, we will test how oxygen sensing enzymes regulate EBNA1 and EBV episome maintenance during latency. We have found that proline and lysine hydroxylases regulate EBNA1 and EBNA2 protein stability and function. We have mapped interaction sites on EBNA1 that bind the lysine hydroxylase PLOD1 and found this interaction essential for EBNA1 protein stability under normoxia. We now propose to investigate how hypoxia regulates the interaction of PLOD1 with EBNA1 to control EBV episome maintenance and persistence during latent infection. These aims are highly integrated with other members of the program project exploring hypoxia effects on related tumor viruses. Together, these aims will provide a framework to understand how viruses respond to hypoxia to promote host cell survival and drive the oncogenic process.