Interferon Regulatory Factor 7 and NPC

描述(申请人提供)：EB病毒(EBV)感染与鼻咽癌(NPC)的发展密切相关。EBV是如何与上皮细胞相互作用实现转化的，人们知之甚少。尽管EBV潜伏膜蛋白1(LMP-1)是EB病毒转化静息B细胞所必需的病毒蛋白，被认为是鼻咽癌的关键分子，但LMP-1在鼻咽癌发生发展中的确切作用尚不清楚。受LMP-1调控的基因之一是干扰素调节因子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。我们发现IRF-7具有致癌潜能，并且在鼻咽癌等人类肿瘤中表达。此外，LMP-1和IRF-7在转化啮齿动物细胞方面具有协同作用。我们推测，IRF-7是LMP-L诱导转化的介质之一，并在EB病毒相关肿瘤的发病机制中发挥作用。拨款中建议的实验将探讨IRF-7和LMP-1是否在鼻咽癌的发病机制中发挥作用。在目标1中，我们将研究IRF-7和NPC之间可能的联系。我们将比较正常鼻咽癌和正常鼻咽癌细胞中IRF-7的表达和激活状态。并用免疫组织化学方法检测鼻咽癌组织中LMP-1和IRF-7之间的关系。目标2将检测IRF-7和LMP-1在鼻咽癌发生发展中的可能作用。我们将制备携带IRF-7或LMP-1的小干扰RNA(SiRNA)的重组逆转录病毒，并将其导入鼻咽癌细胞，并监测裸鼠肿瘤的发展。此外，我们还将LMP-1转化为显性突变体，并检测该显性突变体是否能阻断鼻咽癌的生长。拟议的实验结果应该有助于阐明LMP-1、IRF-7和NPC之间的关系。这项研究将有助于更好地理解LMP-1和IRF-7如何相互作用参与病毒的致病、潜伏和转化。

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.