LncRNA TLNC1通过调控β-catenin促进肝癌发生发展的作用及机制研究

Long noncoding RNAs have been demonstrated to play vital roles in the development and progression of human cancer. However, their biological functions and underlying mechanisms in hepatocarcinogenesis remain largely unknown. In the preliminary study, we identified a novel tumorigenic long noncoding RNA on chromosome 1p36 (termed TLNC1) that was up-regulated in both liver tumor tissues and highly metastatic liver cancer cell line. We also found that high levels of TLNC1 expression were correlated with more frequent vascular invasion, advanced BCLC stage and poor prognosis. Moreover, our data showed that knockdown of TLNC1 significantly reduced cell growth and repressed the invasion and migration of liver cancer cells. WNT/β-catenin pathway plays a key regulatory role in the development and metastasis of liver cancer. Based on the combination of RNA-seq with RNA pull-down, we showed that TLNC1 could directly interact with β-catenin, which then translocated into nucleus and activated its downstream targets, finally contributed to the development and progression of liver cancer. In this project, we will clarify the biological functions of TLNC1 in the development and progression of liver cancer. Additionally, we will illustrate the regulatory mechanism of TLNC1 on wnt/β-catenin pathway. Moreover, we will enlarge the clinical sample size to explore the potential clinical value of TLNC1 and β-catenin.

LncRNA在肿瘤发生发展过程中发挥着关键作用，然而其在肝癌中的生物学功能和分子机制仍有待进一步阐明。前期我们筛选出了一种与肝癌发生发展潜在相关的lncRNA，TLNC1。研究结果显示TLNC1在肝癌组织和高转移潜能的肝癌细胞中高表达，同时与血管侵犯、肿瘤分期和患者预后等密切相关。进一步的研究发现，敲低TLNC1可显著抑制肝癌细胞的生长和侵袭迁移。Wnt/β-catenin通路是肝癌发生和转移过程中的关键调控通路。结合RNA-seq和RNA pull-down实验我们发现，TLNC1可能直接通过与β-catenin相互作用，促进其入核激活下游基因的转录，从而诱导肝癌的发生和转移。在此基础上，本项目拟进一步明确TLNC1在肝癌发生发展过程中的生物学功能；阐明TLNC1调控wnt/β-catenin通路的分子机制；扩大样本量，明确TLNC1与β-catenin在肝癌中的临床应用价值。

LncRNA在肿瘤发生发展过程中发挥着关键作用，然而其在肝癌中的生物学功能和分子机制仍有待进一步阐明。在本课题中，我们通过比较临床肝癌样本及其配对的癌旁正常肝组织，筛选出了一种与肝癌发生发展潜在相关的lncRNA，TLNC1。研究结果显示TLNC1在肝癌组织中的表达显著高于配对的癌旁正常肝组织，同时与肝硬化显著相关。进一步的研究发现，敲低TLNC1可在体内外显著抑制肝癌细胞的生长和转移，而过表达TLNC1可在体内外显著促进肝癌细胞的生长和转移。结合RNA-seq、RNA pull-down实验、Co-IP以及表面等离子体共振分析等实验手段我们发现，TLNC1可与TPR直接相互作用，通过增强TPR与CRM1的相互作用，从而促进p53的出核，导致一系列抗癌因子的表达下调，同时上调了许多癌基因的表达，最终促进了肝癌的生长和转移过程。此外，我们还证明了TLNC1与肝癌患者的总体生存期和无病生存期均密切相关，同时将TLNC1与p53的靶基因p21联合可作为肝癌患者的预后标志物。