Epstein Barr Virus Latency

描述(申请人提供)：非角化性鼻咽癌(NPC)100%与致癌的人类疱疹病毒Epstein-Barr病毒的存在有关。它分为两个亚型：低分化(类型II)和未分化(类型III)。III型是迄今为止最常见的疾病形式。尽管鼻咽癌是一个重大的世界性健康问题，但对它的研究仍然很少。此外，由于它在一个隐蔽的部位发展，最初出现与上呼吸道感染相关的症状，在达到晚期之前往往没有被发现。这一点至关重要，因为早期疾病很容易治愈，而晚期疾病的治疗方法会导致高发病率和复发率，而且没有治疗转移性疾病的有效选择。因此，迫切需要开发针对晚期疾病的新疗法。在这项研究中，我们使用系统生物学技术来确定与鼻咽癌肿瘤生长和转移有关的候选分子和过程。其目的是调查潜在的机制，也可能确定新疗法的靶点。在这项工作中，将建立鼻咽癌肿瘤生长和转移的体外和体内(小鼠)模型。在体外，将使用培养的原代上皮细胞、特征良好的鼻咽癌细胞系和直接从鼻咽癌活检组织中培养的肿瘤细胞。体内异位肿瘤生长和新开发的鼻咽癌原位转移模型将使用异种移植的鼻咽癌细胞株和肿瘤活检标本。这些模型将能够评估在初步研究中已经确定的过程如何有助于疾病的发展和进展。1.基于III型鼻咽癌中PI3K/Akt/mTOR信号通路的优先失控，验证II型鼻咽癌和III型鼻咽癌在分子遗传水平上的差异。这种放松管制是否会使III型肿瘤更容易受到针对这一途径的药物的影响，以及这些药物是否会阻碍肿瘤在体内的侵袭和转移行为。2.研究趋化因子CCL5(RANTES)在上皮性鼻咽癌细胞迁移、侵袭和转移中的作用。3.研究EBV编码的潜伏蛋白LMP1和LMP2a在体内肿瘤生长和转移中的作用，激活PI3linase/Akt/mTor信号通路，诱导RANTES依赖的迁移、侵袭和转移。4.建立EBV相关肿瘤中EBV miRNA表达的定量图谱，特别是鼻咽癌。将聚类算法应用于这些数据集，以确定其在鼻咽癌中表达上调或下调的miRNAs，以确定其靶基因，并最终评估这些基因在体内肿瘤生长和转移中的作用。 公共卫生相关性： 鼻咽癌是一个重要的世界性健康问题，尤其是在华南血统的人群中。由于它通常是在进展到晚期后被诊断出来的，预后很差，因此迫切需要开发针对晚期疾病的新疗法。我们采取了多方面的方法来了解调控鼻咽癌肿瘤生长、侵袭和转移的潜在机制，长期目标是开发针对这些过程的新的候选疗法。

DESCRIPTION (provided by applicant): Non-keratinizing nasopharyngeal carcinoma (NPC) is 100% associated with the presence of the oncogenic human herpesvirus Epstein-Barr virus. It is divided into two sub types: poorly differentiated (type II) and undifferentiated (type III). Type III is by far the most common form of the disease. Although a major world heath problem, NPC remains understudied. Furthermore, because it develops in an occult site and initially presents with symptoms associated with upper respiratory tract infection, it often remains undetected until it has reached an advanced stage. This is critical because early stage disease is readily treatable and potentially curable, whereas therapeutics for advanced stage disease result in high morbidity and relapse rates and there are no effective options for treating metastatic disease. Therefore there is a pressing need for the development of new therapies that target advanced disease. In this study we are using systems biology techniques to identify candidate molecules and processes that contribute to NPC tumor growth and metastasis. The intent is to investigate underlying mechanisms that may also identify targets for new therapies. In this work in vitro and in vivo (mouse) models of NPC tumor growth and metastasis will be developed. In vitro, cultured primary epithelial cells, well characterized NPC cell lines and tumor cells cultured directly from NPC biopsies will be used. In vivo ectopic tumor growth and a newly developed orthotopic NPC metastasis model will be used employing xenotransplanted NPC cell lines and tumor biopsy samples. These models will allow the evaluation of how processes, already identified in preliminary studies, contribute to disease development and progression. These are: 1. to test the idea that type II and type III NPC are distinct at the molecular genetic level based on preferential deregulation of the PI3kinase/Akt/mTOR signaling pathway in type III NPC. Does this deregulation make type III tumors more vulnerable to drugs that target this pathway and will such drugs impede the invasive and metastatic behavior of the tumors in vivo. 2. To study the role of the chemokine CCL5 (RANTES) in mediating epithelial and NPC tumor cell migration, invasion and metastasis. 3. Study the role of the EBV encoded latent proteins LMP1 and LMP2a in tumor growth and metastasis in vivo, activation of the PI3linase/Akt/mTOR signaling pathway and induction of RANTES dependent migration, invasion and metastasis. 4. To develop quantitative profiles of EBV miRNA expression in EBV associated tumors with special emphasis on NPC. Apply clustering algorithms to these data sets to define miRNAs whose expression is up- or down-regulated in NPC in order to identify their target genes and ultimately assess the role of these genes in tumor growth and metastasis in vivo. PUBLIC HEALTH RELEVANCE: Nasopharyngeal carcinoma is an important world health problem especially in people of Southern Chinese origin. Because it is usually diagnosed after progression to an advanced stage, with poor prognosis, there is a pressing need for the development of new therapies that will target the advanced stages of disease. We have taken a multi-faceted approach to understanding the underlying mechanisms regulating NPC tumor growth, invasion and metastasis with the long term goal of developing new candidate therapies that target these processes.