Project 4: Regulation of EBV Latency and Oncogenesis by Hypoxia

摘要： EB 病毒 (EBV) 一种与多种淋巴和上皮细胞相关的人类伽马疱疹病毒 恶性肿瘤。与所有癌症一样，EBV 相关癌症必须在营养耗尽的环境中竞争并生存 环境。对氧气波动的适应是大多数癌症的标志。在本提案中，我们调查 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 在原发感染期间如何调节宿主缺氧反应。我们的初步数据表明 EBNA1 EBNA2可以结合并调节控制缺氧反应的细胞基因，包括缺氧诱导 因子 1 α (HIF1A)。我们将检验 EBV 感染调节宿主对缺氧反应的假设 促进受感染细胞的存活并促进肿瘤发生。对于目标 2，我们将研究病毒如何 表观基因组由氧传感酶调节。 EB 病毒相关伯基特淋巴瘤 (BL) 和上皮细胞 已知恶性肿瘤会获得高 DNA 甲基化，通常称为 CpG 岛甲基化 表型（CIMP）。我们将研究如何通过氧敏感控制来调节 DNA 甲基化 TET2 酶并探索缺氧如何促进 CIMP 和抑癌基因沉默。对于 目标 3，我们将测试氧传感酶如何在潜伏期调节 EBNA1 和 EBV 附加体维持。 我们发现脯氨酸和赖氨酸羟化酶可调节 EBNA1 和 EBNA2 蛋白的稳定性和功能。 我们在 EBNA1 上绘制了与赖氨酸羟化酶 PLOD1 结合的相互作用位点，并发现了这种相互作用 对于常氧条件下 EBNA1 蛋白的稳定性至关重要。我们现在建议研究缺氧如何调节 PLOD1 与 EBNA1 相互作用以控制潜伏感染期间 EBV 游离体的维持和持续存在。 这些目标与该计划项目的其他成员高度结合，探索缺氧对相关疾病的影响。 肿瘤病毒。总之，这些目标将提供一个框架来了解病毒如何应对缺氧 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.