Interferon Regulatory Factor 7 and NPC

描述（由申请人提供）：EB病毒（EBV）感染与鼻咽癌（NPC）的发生密切相关。EB病毒如何与上皮细胞相互作用以实现转化知之甚少。尽管EBV潜伏膜蛋白1（LMP-1）是EBV转化静息B细胞所需的病毒蛋白，并被认为在NPC的发生发展中起关键作用，但LMP-1在NPC发生发展中的确切作用仍不确定。受LMP-1调节的基因之一是干扰素（IFN）调节因子7（IRF-7）。LMP-1诱导IRF-7的表达，并通过磷酸化和核转位激活IRF-7蛋白。然而，对LMP-1和IRF-7相互作用的功能知之甚少。我们已经发现IRF-7具有致癌潜力，并且在人类癌症如NPC中表达。此外，LMP-1和IRF-7在转化啮齿动物细胞中具有协同作用。我们假设IRF-7是LMP-1诱导转化的介质之一，并且在EBV相关肿瘤的发病机制中起作用。该基金中拟议的实验将解决IRF-7及其与LMP-1的组合是否在NPC的发病机制中发挥作用。在目标1中，我们将研究IRF-7与NPC之间的可能联系。IRF-7的表达和激活状态（即，核IRF-7）在正常上皮细胞和NPC细胞之间进行比较。此外，LMP-1和IRF-7在NPC中的关系将通过使用免疫染色来检查。IRF-7和LMP-1在鼻咽癌发展中的可能作用将在目标2中进行测试。我们将制备携带针对IRF-7或LMP-1的小干扰RNA（siRNA）的重组逆转录病毒，并将病毒导入NPC细胞，并监测裸鼠肿瘤的发展。此外，我们还将构建LMP-1转化的显性突变体，并测试显性突变体是否能阻断NPC的生长。从拟议的实验结果应该阐明LMP-1，IRF-7和NPC之间的关系。这项研究将有助于更好地了解LMP-1和IRF-7如何相互作用，参与病毒的发病机制，潜伏期和转化。

DESCRIPTION (provided by applicant): Epstein-Barr virus (EBV) infection has been closely associated with the development of nasopharyngeal carcinoma (NPC). How EBV interacts with epithelial cells to achieve transformation is poorly known. Although EBV latent membrane protein 1 (LMP-1) is the viral protein required for EBV transformation of resting B cells and proposed to be a critical player in NPC, the exact role of LMP-1 in the development of NPC is still uncertain. One of the genes regulated by LMP-1 is interferon (IFN) regulatory factor 7 (IRF-7). LMP-1 induces the expression of IRF-7, and activates IRF-7 protein by phosphorylation and nuclear translocation. However, little is known about the functions of the LMP-1 and IRF-7 interaction. We have found that IRF-7 has oncogenic potential and is expressed in human cancers, such as NPC. Also, LMP-1 and IRF-7 have a cooperative effect in transforming rodent cells. We hypothesize that IRF-7 is one of the mediators of LMP-l-induced transformation, and plays a role in the pathogenesis of EBV-associated tumors. The proposed experiments in the grant will address whether IRF-7 and in combination with LMP-1 plays a role in the pathogenesis of NPC. In Aim 1, we will examine the possible linkage between IRF-7 and NPC. The expression and activation status of IRF-7 (i.e., nuclear IRF-7) will be compared between normal epithelial and NPC cells. Also, the relation between LMP-1 and IRF-7 in NPC will be examined with the use of immunostaining. The possible role of IRF-7 and LMP-1 in the development of NPC will be tested in Aim 2. We will make recombinant retroviruses carrying small interfering RNA (siRNA) for IRF-7 or LMP-1, and introduce the viruses to NPC cells, and monitor the development of tumors in nude mice. In addition, we will make the dominant mutant for LMP-1 transformation, and test if the dominant mutant could block the growth of NPC. The results from proposed experiments should shed light on the relation among LMP-1, IRF-7, and NPC. This study would lead to a better understanding of how LMP-1 and IRF-7 interact to participate in viral pathogenesis, latency, and transformation.