长链非编码RNA LOC284454作为ceRNA促进鼻咽癌侵袭转移

We previously identified LOC284454, a long non-coding RNA that is overexpressed in nasopharyngeal carcinoma (NPC); however, its biological function remains completely unknown. We found that LOC284454 expression was strongly associated with metastasis and poor outcomes in NPC patients. In addition, high levels of LOC284454 were detected in the plasma of NPC patients. Our preliminary data demonstrated that LOC284454 knock-down inhibited invasion and migration in NPC cells in vitro and in vivo. By analyzing the gene-expression transcriptome profile of LOC284454 knock-down NPC cells, we found that LOC284454 might function as a competing endogenous RNA (ceRNA) that regulates the TRAF1 gene and the downstream signaling pathways, such as NF-κB, to promote invasion and migration in NPC cells. TRAF1 is also a key component of the nasopharyngeal epithelial carcinogenesis signaling pathway associated with Epstein-Barr virus (EBV). In this study we will elucidate three aspects associated with the function of LOC284454 in NPC and the mechanism by which LOC284454 promotes NPC progression. First, LOC284454 enhances invasion and metastasis in NPC cells by modulating the TRAF1 gene; Second, LOC284454 cooperatively regulates EBV downstream signaling pathways; Third, LOC284454 secrets into the NPC microenvironment by exosomes where it remodels the premetastatic niche. This study will reveal the biological function of LOC284454, and these findings will provide further insight into the carcinogenesis mechanisms of NPC.

我们前期发现一个功能未知的长链非编码RNA LOC284454在鼻咽癌中表达上调与转移及不良预后密切相关，且在患者血浆中同样高表达；细胞和动物模型中初步证实siRNA敲低LOC284454表达后可抑制鼻咽癌细胞侵袭转移能力；分析敲低LOC284454前后鼻咽癌细胞中的转录组数据结合生物信息学预测和初步分子生物学实验验证，我们提出LOC284454作为ceRNA调控TRAF1及下游NF-κB等信号通路促进鼻咽癌侵袭转移的科学假说，而TRAF1又是EB病毒促进鼻咽上皮癌变信号通路的关键节点。本项目将从LOC284454通过TRAF1增强鼻咽癌细胞侵袭转移能力，对EB病毒LMP1下游信号通路的协同调控，以及通过外泌体改造鼻咽癌转移前龛三方面探讨LOC284454在鼻咽癌侵袭转移过程中的作用和机制；本项目的完成不仅将初步揭示LOC284454的生物学功能，并将进一步增进对鼻咽癌发生发展机制的了解。

我们通过用全蛋白质谱检测LOC284454相关的编码蛋白，进而用生物信息学分析LOC284454调控蛋白的功能与富集的信号通路，鉴定lncRNA LOC284454在鼻咽癌组织和血浆中高表达与患者不良预后相关，可作为鼻咽癌患者血浆诊断和预后新的分子标志物，促进鼻咽癌细胞的增殖、迁移和侵袭。它通过TRAF1增强鼻咽癌细胞侵袭转移能力，对EB病毒LMP1下游信号通路的协同调控，与（Epstein-Barr virus infection）和剪切体（Spliceosome）相关通路相互作用参与基因调控、外泌体以及可变剪切。另外通过收集鼻咽癌患者和正常人全血，采用QIAGEN公司的试剂盒提取血清RNA，采用Thermo公司的逆转录试剂进行RT-PCR。我们采用SYBR-qPCR的实验方法进行初步的检测，且设计了TaqMan探针，采用特异性较好的TaqMan-qPCR的实验方法进一步验证，评估临床参数对LOC284454对鼻咽癌表达水平的影响，我们发现LOC284454在鼻咽癌患者血清中表达明显上调，因此LOC284454可能作为鼻咽癌的血清分子标志物。