大规模挖掘肺癌预后的长非编码RNA分子标记

Lung cancer is the leading cause of cancer mortality in China. Despite recent advances in therapy, the overall 5-year survival has not changed in the last several decades and remains at 15%. Nearly 50% of patients with stages I and II non-small cell lung cancer (NSCLC) will die from recurrent disease despite surgical resection. No reliable molecular predictors are currently available for identifying those at high risk for developing recurrent disease. As a consequence, it is not possible to select those high-risk patients for more aggressive therapies and assign less aggressive treatments to patients at low risk for recurrence. .Long non-coding RNAs (lncRNA) are non-protein coding transcripts longer than 150-200 nucleotides. The new emerging lncRNAs are key regulatory molecules that have numerous molecular functions, including modulating transcriptional patterns, regulating protein activities, serving structural or organizational roles, altering RNA processing events, and serving as precursors to small RNAs. Aberrant expression or copy number changes of lncRNAs are associated with multiple cancers. So far, few studies have been performed in lung cancer. .The major objective of this application is 1) to develop a novel lncRNA signature that is highly predictive of which stage I lung cancer patients may benefit from more aggressive therapy and 2) to identify several lncRNA as promising druggable targets in cancer therapy. Our central hypothesis is that dysregulation of lncRNAs leads to lung cancer initiation and progression and lncRNAs can be identified as prognostic biomarkers and therapeutic targets. To test this hypothesis, we propose to accomplish the following aims. Aim 1 will perform RNA-Seq in 50 stage I NSCLC patients with good outcome (survival >2.5 years) and 50 with bad outcome (<1 years). Aim 2 will reconstruct transcriptome from the RNA-Seq data and further identify lncRNAs that are dysregulated in lung tumor tissues. Aim 3 will develop a novel lncRNA-based expression signature predictive of overall survival and disease recurrence in stage I NSCLC patients. Aim 4 will validate and refine this new signature in an independent population of 100 stage I NSCLC patients using qRT-PCR. Finally, the functional roles of several selected lncRNAs in cell proliferation, apoptosis, migration and metastasis will be evaluated by siRNA assays in Aim 5. .At the completion of this project, we will identify a powerful lncRNA-based expression signature that can accurately predict overall survival and recurrence of stage I NSCLC patients. Such results are highly significant and timely as the identified genomic signature will not only help clinicians in selecting the most effective treatment options for stage I lung cancer, but also provide new targets for anti-cancer therapy in addition to fundamentally advancing the knowledge of lncRNA in lung cancer progression and recurrence.

大约50%I期和II期非小细胞肺癌病人在手术后仍死于癌症复发，但目前还没有可靠的分子预测方法来鉴定肺癌病人的临床结果。lncRNA是细胞中一类转录本长度在150-200个核苷酸以上的非编码RNA分子。lncRNA在哺乳动物的基因调控中发挥非常重要作用。许多疾病如癌症存在lncRNA的异常表达，但未见肺癌这方面的相关研究报道。本项目研究假设是lncRNA参与了肺癌转移复发的基因调控。主要研究内容是通过大规模RNA-Seq测序分析，系统地发现在肺癌中特异性表达的lncRNA，获得能有效地预测肺癌病人生存期和复发的lncRNA表达谱,进一步功能分析若干lncRNA，揭示其在肺癌转移复发中的分子机制。本项目完成后，预期发展的分子预测方法能为肺癌病人治疗方案提供重要参考，延长病人生存期和提高生活质量。同时有望筛选出抗肺癌转移复发的若干药物新靶点，从而为将来肺癌病人的个性化治疗打下基础。

lncRNA是细胞中一类转录本长度在150-200个核苷酸以上的非编码RNA分子。lncRNA在哺乳动物的基因调控中发挥非常重要作用。许多疾病如癌症存在lncRNA的异常表达，但肺癌相关研究报道并不见。本项目主要通过大规模RNA-Seq测序分析，系统地发现在肺癌中特异性表达的lncRNA，获得有效地预测肺癌病人生存期和复发的lncRNA，并功能分析若干lncRNA，揭示其在肺癌转移复发中的分子机制。特别地，我们首次发现了在肺癌中高表达的新lncRNA （Lung cancer associated transcript 1，LCAT1），LCAT1表达越高，肺癌病人的预后越差。采用双荧光报告基因、RIP、细胞学和小鼠试验等手段，发现了敲低LCAT1能抑制肺癌细胞增殖和迁移，LCAT1通过竞争性吸附的miR-4715-5p，从而上调其内源性目标基因RAC1（即Rac family small GTPase 1）的活性。RAC1小分子抑制剂（EHop-016）和一线化疗药物Taxol的联合用药能协同促进肺癌细胞的凋亡。本项目揭示了LCAT1–miR-4715-5p–RAC1/PAK1轴在肺癌发生发展中的作用机制，有望成为新的肺癌预后标记物和抗肿瘤治疗的新靶点。EHop-016和Taxol的联合用药对于LCAT1高表达的肺癌病人的疗效会更好，有必要进一步做相关的临床试验验证其疗效。