lncRNA RGMB-AS作为ceRNA调控NSCLC中RGMB表达的分子机制及其临床意义

Long noncoding RNAs (lncRNAs) are emerging as new players in gene regulation and are associated with the development of cancers. The Repulsive Guidance Molecules B (RGMB) has been implicated as a tumor suppressor, which inhibit lung cancer metastasis, in our previous study. LncRNA RGMB-AS might be the main regulator of RGMB expression. But the underlying mechanisms are not entirely clear. In the present study we examined the alteration in expression of RGMB induced by lncRNA RGMB-AS using WB and polymerase chain reaction (PCR). The thereby role of RGMB-AS in lung cancer metastasis was investigated in vitro and in vivo. Mechanistically, RGMB-AS was further investigated whether directly bind to miRNA and effectively functioned as a sponge for miRNAs to modulate the expression of RGMB. The present study might reveal the role of lncRNA RGMB-AS in tumor suppression and survival prediction in lung cancer patients. This contributes to a better understanding of RGMB-AS, as a ceRNA to impair miRNAs-dependent RGMB downregulation, and provides a rationale for the potential development of lncRNA-based targeted approaches for the treatment of NSCLC.

我们前期发现排斥性导向分子 (RGM)B在非小细胞肺癌（NSCLC）中出现高频的低表达, 且与肿瘤侵袭转移密切相关；但RGMB在NSCLC中下调的机制不清楚。我们近期一系列预实验结果提示：RGMB上游反义方向存在重要调控因子lncRNA RGMB-AS，其可能作为ceRNA竞争性结合miR93等miRNAs，调控NSCLC中RGMB表达。为验证这一假说，本项目拟先通过RNA干扰/过表达技术、pulldown等，探讨RGMB-AS对RGMB的调控，并在体外观察其在NSCLC中作用；然后通过生物信息学分析结合报告基因实验，筛选RGMB-AS的靶向miRNAs，并验证miRNAs 与RGMB的结合及对其表达的调控；最后深入研究RGMB-AS作为ceRNA通过miRNA对RGMB调控的分子机制，并在体内和临床样本中验证RGMB-AS对NSCLC侵袭转移的影响和临床意义，为NSCLC诊疗提供新靶点。

肺癌仍是目前最普遍和最致命的癌症。肺癌发生和发展的分子机制仍不清楚。长链非编码RNA（lncRNA）在肿瘤发生发展中的重要性日趋受到重视，目前在肺癌中的作用仍有待研究。我们通过lncRNA表达谱芯片和生物信息学分析，筛选到对肺腺癌和正常肺组织基因表达差异起重要作用的关键lncRNA RGMB-AS。本项目主要从临床研究、分子、细胞、动物不同水平明确RGMB-AS表达与肺腺癌临床特征的关系，探讨lncRNA RGMB-AS对肺腺癌细胞生物学行为的影响及其分子机制。结果发现lncRNA RGMB-AS是一种新的长非编码反义转录物。与正常肺组织相比，肺腺癌组织中lncRNA RGMB-AS表达下调。此外，lncRNA RGMB-AS在体内抑制肺癌细胞生存，在体外抑制肺癌细胞生长侵袭。lncRNA RGMB-AS的低表达与肺腺癌预后差显著相关。在机制上，lncRNA RGMB-AS通过与RBM形成复合物，调控RGMB等靶基因的表达水平，进而抑制细胞生长和侵袭。研究结果提示lncRNA RGMB-AS在肿瘤发生发展中作为抑癌基因起重要作用，表明lncRNA RGMB-AS可能是有潜力的治疗候选靶点之一。本研究为深入认识lncRNA在肺癌发病过程中的作用及机制提供了新的理论依据。