同一基因来源的circRNA-MAPKAPK5.23与lncRNA-MAPKAPK5-AS1共同调控MAPKAPK5在人群肺癌发生发展中的作用机制研究

Both anti-sense long non-coding RNA (AS-lncRNA) and circular RNA (circRNA) were considered as key regulator in epigenetic mechanisms to regulate gene expression, and were closely related to tumorigenesis, invasion and metastasis. The mechanism of how the two ncRNAs co-regulate the target genes remains unclear. We analyzed our previous RNA-seq data and identified a significantly lower expression of AS-lncRNA-MAPKAPK5-AS1 in cancer tissues compared to that in the corresponding non-cancerous tissues, and it was positively correlated with the expression level of the corresponding host tumor suppressor gene MAPKAPK5. The bioinformatic analysis found there were several reverse complement regions between lnc-MAPKAPK5-AS1 and the promotor of MAPKAPK5. Also, there was a circular RNA-MAPKAPK5.23 in MAPKAPK5 region which shared a common miRNA has-miR-4755-3p binding site with AS-lncRNA MAPKAPK5-AS1. Further qPCR confirmed that circ-MAPKAPK5.23 was positively correlated with the expression level of MAPKAPK5. Our findings suggest lnc-MAPKAPK5-AS1 might function as a ceRNA which competes the miRNA binding site has-miR-4755-3p with circ-MAPKAPK5.23 in co-regulating the same host tumor suppressor gene MAPKAPK5 in lung cancer development. Therefore, this project intends to assess the associations of lnc-MAPKAPK5-AS1, circ-MAPKAPK5.23 expression with lung cancer risk as well as prognosis. A series of experiments using stably transfected lung cancer cell lines will be employed to verify the inhibition effects of lnc-MAPKAPK5-AS1 and circ-MAPKAPK5.23 on lung cancer cell invasion and metastasis, and to explore the mechanism of lnc-MAPKAPK5-AS1, circ-MAPKAPK5.23 on lung cancer risk and prognosis. This project will help to clarify the mechanism and pathology of lung cancer and provide scientific evidences for early diagnosis and treatment.

反义长链非编码RNA和环状RNA通过表观遗传学机制调控基因表达，参与肿瘤发生发展、侵袭转移等过程，尚不清楚二者如何联合调控靶基因表达。课题组前期预实验发现lnc-MAPKAPK5-AS1在肺癌组织中低表达，靶基因MAPKAPK5在癌组织中低表达，二者表达呈正相关。生物信息学分析发现该lncRNA与靶基因启动子有反向互补序列，该区段还有与lncRNA具有共同miRNA结合序列的circ-MAPKAPK5.23，其表达与靶基因呈正相关，提示该lncRNA可与该环状RNA竞争性结合miRNA联合调控靶基因在肺癌发生发展的作用。本项目在预实验基础上，通过大样本单纯病例研究探讨该lncRNA与该环状RNA表达与肺癌发病预后的关联；通过系列体内-体外实验揭示lnc-MAPKAPK5-AS1与circ-MAPKAPK5.23联合调控MAPKAPK5抑制肺癌发生发展的分子机制，为人群肺癌防治提供科学依据。

lnc-MAPKAPK5-AS1在肺癌中通过与靶基因MAPKAPK5相互作用，与人群肺癌发展相关，增加淋巴结转移和远端转移风险，缩短肺癌患者生存期；COX回归模型结果显示lnc-MAPKAPK5-AS1表达上调与肺癌患者生存期短有关，且lnc-MAPKAPK5-AS1高表达能够明显缩短肺癌患者生存期；细胞实验结果显示，高表达lnc-MAPKAPK5-AS1能够促进肺癌细胞增殖、转移、克隆形成，能够促进细胞分裂，抑制细胞凋亡；动物实验发现lnc-MAPKAPK5-AS1能够促进肺癌细胞在裸鼠体内增殖；MAPKPAK5在肺癌患者肿瘤组织中表达上调，其高表达与肺癌患者与肺癌患者远端转移风险增加有关，其高表达与lnc-MAPKAPK5-AS1呈正相关，MAPKAPK5表达较高的患者生存期较低表达患者短；因因circ-MAPKAPK5.23序列特殊，慢病毒载体合成公司反馈经数次尝试仍未能合成包含circ-MAPKAPK5.23序列的质粒，故本项目未能验证其功能。本项目探索了lnc-MAPKAPK5-AS1在促进肺癌发生和发展中所起的促癌作用，为肺癌防治提供了科学依据。项目资助发表了论文3篇，其中SCI论文1篇，中文会议论文2篇；待发表SCI论文1篇。参与培养博士1名（2020年6月毕业）。项目投入科研经费21.0000万元，支出13.1167万元；项目主持人所在单位配套7.5000万元，支出7.5000万元，项目合计投入经费28.5000万元，合计支出20.6167万元，合计剩余经费7.8833万元，剩余经费将用于本项目后续研究及论文发表支出。