长链非编码RNA—LOC154860在结直肠癌发生发展中的作用及机制研究

Colorectal cancer (CRC) is one of the most common human malignant tumors. Large non-coding RNAs (lncRNA) play key roles in gene regulation, including imprinting control, circuitries controlling pluripotency and differentiation, immune responses, chromosome dynamics. LncRNAs are also emerging as important regulatory molecules in development and progression of human tumors. Our previous works have revealed that the expression profile of CRC tissues is significantly different from that of normal colorectal tissues, and found that a novel lncRNA, LOC154860, was upregulated significantly in CRC. Moreover, the overexpression of LOC154860 could prompt the in vitro proliferation of CRC cells and predict poor prognosis of CRC patients. These results suggest that LOC154860 may be a novel RNA molecule with oncogenic function in CRC. Basing on these important new findings, this project plans to further evaluate the effects of LOC154860 on biological behaviors relating with malignant phenotypes of CRC cells from in vitro and in vivo levels using experimental methods of cellular/molecular biology and experimental zoology. By these analyses, we could understand the exact molecular mechanism of LOC154860 in the development and progression of CRC. In addition, this project also plans to analyze the relationship between the expression levels of LOC154860 in CRC tissues and the prognosis or clinical pathological features of CRC, and to further evaluate the application value of LOC154860 as a prognostic and/or predictive marker in CRC. The present study will provide important theoretical and experimental data for explaining the pathogenesis and for the preventing and therapy of CRC, which also could provide important guidance for the diagnosis, therapy and prognosis of CRC.

结直肠癌(CRC)是最常见的恶性肿瘤之一。长链非编码RNA（lncRNA）是一大类参调控性RNA分子，与肿瘤的发生、发展密切相关。申请者前期研究鉴定了一批在CRC中差异表达的lncRNA分子，其中LOC154860不仅在CRC组织中显著上调，且可促进CRC细胞的体外增殖，并与CRC患者不良预后相关，提示其可能是一个新的癌基因。本项目拟在这些重要的新发现的基础上，应用细胞/分子生物学、实验动物学等手段从体外细胞水平及活体水平系统研究LOC154860对CRC细胞恶性表型相关的细胞生命活动的影响，并进一步阐明其分子机制；同时结合临床病例，分析LOC154860表达和CRC患者预后及肿瘤临床病理表型的关系，评估LOC154860分析在指导治疗、判断预后中的临床应用价值。研究结果可为解释CRC的发病机制及防治在lncRNA调节水平提供新的实验和理论依据，并为CRC的诊断、治疗和预后提供重要指导。

结直肠癌(CRC)是最常见的恶性肿瘤之一。长链非编码RNA（lncRNA）是一大类参调控性RNA 分子，参与基因印迹控制、细胞增殖与分化、免疫应答和染色质动力学等一系列生理病理过程，尤其与肿瘤的发生、发展密切相关。申请者前期研究鉴定了一批在CRC 中差异表达的lncRNA 分子。本项目在此基础上，主要以FEZF1-AS1（原名LOC00154860)和UCA1为研究对象，开展了深入的功能及机制研究。主要研究内容及结果包括：（1）扩大的临床样本分析显示，FEZF1-AS1和UCA1分别在62%和59%的CRC组织中表达上调，并与更差的患者预后相关。（2）体内外功能实验显示，FEZF1-AS1能促进CRC细胞增殖、迁移、侵袭和细胞周期进程，并抑制细胞凋亡。UCA1能促进CRC细胞增殖和肿瘤发生并通过抑制细胞凋亡降低CRC细胞对化疗药物5-FU的敏感性。（3）运用RNA-seq、RNA pull-down实验及蛋白质谱等手段，揭示了FEZF1-AS1通过与PKM2结合，上调及活性，激活PKM2/STAT3信号通路，发挥促癌作用。（4）UCA1可竞争性结合miR-204-5p，阻断miR-204-5p对其靶基因RAB22A、BCL2、CREB1的抑制而发挥促癌作用；首次发现CREB1在CRC中表达上调，是miR-204-5p的靶基因并发挥癌基因功能。本项目揭示了两个在CRC中显著上调的lncRNA——FEZF1-AS1和UCA1，并系统研究了其在CRC中的功能、机制及临床应用价值，研究结果可为解释CRC的发病机制及防治在lncRNA 调节水平提供新的实验和理论依据，并为CRC 的诊断、治疗和预后提供重要指导。