胶质瘤中长链非编码RNA HOTAIR功能网络的解析及其分子机制的研究

Glioblastoma (GBM) is the most common and malignant primary brain tumor in adults. Patients with newly diagnosed glioblastoma have a median survival of approximately 1 year which mainly resulted from its poor responses to all therapeutic modalities . It's reported non-coding RNAs and mRNAs are extensively involved in the pathobiology and malignant progression of various kinds of cancer. We profiled the lncRNA expression signatures in 220 gliomas， and for the first time in glioma,identified that expression of HOTAIR was positivetly correlated with glioma grade and poor prognosis. Multivariate Cox regression analysis revealed that HOTAIR was an independent prognostic factor in GBM patients. GSEA analysis indicated that HOTAIR regulateing-gene-sets were enriched in cell cycle progression. Based on our previous study, we first aim to investigate the mechanism of functional domain of HOTAIR positively promote cell cycle progression through PRC2 or LSD1 complex.Second, we use a cell knock-out model system and whole transcriptom sequencing thachology to establish the comprehensive regulatory network of HOTAIR on both mRNA and short non-coding RNA (miRNA and snoRNA). Next we plan to identify the mechanism of HOTAIR-short non-coding RNA network, whick can modulate the transcriptional activity of β-catenin pathway through neuclear recrutment of PKM2 and β-catenin .Moreover,a molecular connection of SNORNA and cell cycle progression will be further investigated. The present study may provide insides for understanding the comprehensive networks of HOTAIR on cell cycle progression as well as β-catenin pathway in glial cancers. Morever, it will provide rationals for a new biomarker and treatment stratgy in gliomas.

前期工作对220例胶质瘤患者临床资料和组织样本基因表达谱研究发现，长链非编码RNA-HOTAIR是胶质瘤独立预后因子；其表达水平与β-catenin转录依赖的胶质瘤分子分型密切相关；与胶质瘤组织中细胞周期蛋白的表达呈正相关。 本项目在对上述样本mRNA/lncRNA表达谱分析基础上，研究HOTAIR通过PRC2/LSD1对细胞周期蛋白的正向调控作用；以胶质瘤细胞中HOTAIR敲除后全转录组测序为基础，在编码基因和短非编码RNA(miRNA与snoRNA)两个层面构建HOTAIR复杂功能网络，研究HOTAIR与mRNA/miRNA/snoRNA 间互作关系；阐明HOTAIR通过调节PKM2参与β-catenin调控细胞周期的分子机制，并探索HOTAIR通过调节某些snoRNA对细胞周期的调控作用。 本研究可揭示HOTAIR对细胞周期调控的分子机制，为发现新的胶质瘤临床标志分子提供实验依据。

本项目在对220例胶质瘤患者临床资料和组织样本样本mRNA/lncRNA表达谱分析基础上，在本项目的支持下，我们揭示了HOTAIR在GBM和正常脑组织中表达有明显差异，与胶质瘤级别紧密相关，并预示不良预后，是指导预后的独立危险因素；进一步研究发现HOTAIR通过表观遗传学调控NLK基因的表达，促进β-catenin与TCF/LEF的结合，激活Wnt信号通路；构建了与细胞周期相关的HOTAIR正相关基因核心网络，揭示了HOTAIR调控胶质瘤细胞周期进展依赖于其5’功能域与EZH2形成复合体行使功能。我们首次揭示核仁小RNA（snoRNAs）SNORD76在恶性胶质瘤中低表达，抑制胶质瘤细胞的增殖；EZH2表达随胶质瘤级别升高而增加，与不良预后有关，是胶质母细胞瘤患者独立预测因子。本项目的研究圆满完成了项目预期，并进一步取得了丰硕的研究成果。