LncRNA-CSCL分子网络重塑肺癌干细胞niche介导化疗抵抗的关键作用及机制

Lung cancer is the most common malignant cancer both in incidence and mortality in China. Although chemotherapy drugs initially effective, but most patients will subsequently relapse and the prognosis is poor. So looking for the underlying molecular basis is of great significance for overcoming the barrier of drug resistance.At present,it has been suggested that cancer stem cells or lncRNA may mediate the therapy resistance, but these researches are still in their early stage. Our group persists in the research of lung cancer recurrence and metastasis and our previous works showed key role of several lncRNAs in the epigenetic regulation of tumor.To explore the key molecular involved in the recurrence and therapy resistance of lung cancer, our previous works performed high-through gene screening base on both of the drug-resistant lung cancer cell lines and lung cancer biopsy specimens. We found a new molecular, named as lncRNA-CSCL, remodels tumor microenvironment (niche) through regulation of "crosstalk" between lung cancer stem cells and macrophages, which possibly leads to lung cancer chemotherapy resistance. While PI3K/Akt signaling pathway plays a key role in the "hub". In this study, we will explore the key mechanisms of lncRNA-CSCL molecular network/lung cancer stem cell mediated drug resistance by cell and mouse model,and even clinical specimens, eventually to provide new strategies for the prevention and treatment of lung cancer.

肺癌的发病率及死亡率在我国恶性肿瘤中最高，且日趋增多，危害巨大。化疗药物早期多有效，但容易产生耐药且预后很差，故阐明潜在的分子基础对破解临床肺癌化疗抵抗的难题意义重大。有研究提示肿瘤干细胞或lncRNA参与了化疗抵抗，但该方面研究尚处于初期。申请者长期致力于肺癌相关机制的研究，前期研究已揭示了多个lncRNAs调控肿瘤的表观遗传机制。为寻求肺癌耐药的关键“因子”，基于前期建立的耐药细胞模型及二次活检肺癌标本进行的肺癌干细胞和lncRNA的双重筛选，申请者发现：一个新分子lncRNA-CSCL，可通过调控肺癌干细胞与巨噬细胞的“crosstalk”重塑肺癌干细胞niche（微环境），并介导了肺癌化疗抵抗，而PI3K/Akt信号通路可能发挥了关键的“枢纽”作用。本研究拟通过细胞及小鼠模型，结合临床样本，探讨lncRNA-CSCL分子网络调控肺癌干细胞介导耐药的关键机制，为肺癌防治提供新策略。

本研究表明LncRNA参与肺癌干细胞的调控，包括明确了LncRNA参与维持肺癌干细胞干性。通过体内及体外研究，研究了LncRNA-CSCL调控相关信号通路的表观调控机制。通过包括RIP、RNApull-down及质谱分析、FISH等分子生物学技术，研究LncRNA-CSCL对下游靶基因调控的分子机制。明确了LncRNA-CSCL以及下游靶基因调控肺癌干细胞重塑肿瘤微环境中的作用及部分机制，包括：1.LncRNA调控肺癌干细胞对肺癌niche的调控作用，明确调节肺癌干细胞LncRNA-CSCL对肺癌相关巨噬细胞趋化作用。明确LncRNA-CSCL调控肺癌表达miRNAs，并验证其介导肺癌干细胞/肿瘤相关巨噬细胞“crosstalk"的机制。2.探讨肿瘤相关调控因子反馈性调控肺癌干细胞LncRNA-CSCL的表达，包括a.明确肿瘤相关巨噬细胞分泌的IL-6/IL-11对肺癌干细胞LncRNA表达的反馈性作用。b. 针对相关LncRNA启动子，进行体外细胞荧光素酶报告基因检测，验证肿瘤相关巨噬细胞通过分泌IL-6/IL-11反馈性调控相关LncRNA的表达。3.通过组织FISH技术，探讨LncRNA/miRNA调控肺癌干细胞/巨噬细胞“crosstalk"重塑肿瘤niche的分子病理学特征。本项目如期完成如下目标：通过细胞及小鼠模型，结合临床样本，探讨了ncRNA调控肺癌干细胞介导化疗抵抗及调控的关键作用，并解析其表观调控机制。研究ncRNA分子网络通过调控肺癌干细胞与肿瘤巨噬细胞“crosstalk”重塑肿瘤niche的生物学功能。揭示了LncRNA参与调控肺癌化疗耐药的部分新机制，为潜在的临床干预新策略提供依据。