基于lncRNA-RP11-274H2.3/NF-κB/IL-6信号轴研究蟾毒灵逆转肺癌奥希替尼耐药机制

Osimertinib, a third generation EGFR inhibitor, has a significant effect on lung cancer patients with common EGFR mutations and T790M mutations. It is expected to be the first-line treatment for EGFR-mutant non-small cell lung cancer. However, the development of acquired resistance to osimertinib can not be avoided. The precise mechanisms of resistance to osimertinib remain largely unknown. There is not effective strategies to prevent and/or overcome acquired resistance to this agent. LncRNA plays an important role in tumor progression and drug resistance. By using RNA Microarray analysis, we found that LncRNA-RP11-274H2.3 (a new transcript) and IL-6 were highly expressed in the osimertinb-resistant cells, and bufalin could down-regulate RP11-274H2.3 and IL-6 expression levels for the first time. According to the model of LncRNA function, bioinformatics prediction and our previous research results, we speculate that RP11-274H2.3 induces the resistance to osimertinib by recruiting NF-κB, promoting IL-6 transcription and activating its downstream signaling pathway. Bufalin may reverse the resistance to osimertinib by down-regulating RP11-274H2.3 and inhibiting NF-κB/IL-6 axis. Based on these results, we will reveal the mechanisms of RP11-274H2.3-induced resistance to osimertinib and bufalin reverses osimertinib resistance by using Mass Spectrometry、RIP、 CHIP、Deletion Mapping and Luciferase reporter assay. Our study will provide a novel strategy for development of new antitumor drugs and reversion of osimertinib resistance.

第三代靶向药物奥希替尼对EGFR常见突变及T790M耐药突变的肺癌患者具有显著的疗效，但耐药无法避免，目前耐药机制未被完全阐明。前期研究中我们应用转录组芯片首次发现一个全新的LncRNA-RP11-274H2.3和IL-6在奥希替尼耐药细胞中显著高表达；蟾毒灵可下调RP11-274H2.3和IL-6表达水平，增强奥希替尼抗肿瘤效果。根据LncRNA作用方式、生物信息学预测及前期研究结果，我们推测RP11-274H2.3通过招募NF-κB促进IL-6转录并激活其下游信号通路诱导奥希替尼耐药；蟾毒灵通过下调RP11-274H2.3抑制NF-κB/IL-6信号轴逆转奥希替尼耐药。本项目拟应用质谱分析、RIP、CHIP、结合位点鉴定及双荧光素酶报告基因等技术，从临床、细胞、动物层面深入探讨RP11-274H2.3诱导奥希替尼耐药的机制及蟾毒灵的干预作用，为开发抗癌中药及防治靶向药物耐药提供理论依据

肺癌是全球发病率和死亡率最高的恶性肿瘤，其中非小细胞肺癌（NSCLC）约占80%-85%，五年生存率不足20%。以第三代表皮生长因子受体酪氨酸酶抑制剂（EGFR-TKIs）奥希替尼为代表的靶向治疗为EGFR突变的晚期肺癌患者带来了希望，但耐药的产生限制了患者临床获益，因此深入研究NSCLC奥希替尼性耐药的机制及防治策略，具有重要的临床价值及科学意义。近年来研究发现，长链非编码RNA（lncRNA）在肿瘤发生发展及治疗抵抗等方面扮演重要角色，但lncRNA是否参与非小细胞肺癌奥希替尼耐药，目前尚不明确。蟾毒灵是中药蟾酥、干蟾皮的主要抗肿瘤活性成分，具有良好的抗肺癌作用，可通过PI3K/AKT等通路逆转吉非替尼耐药，但其是否通过调控lncRNA逆转奥希替尼耐药目前无相关报道。本项目在前期研究的基础上，主要开展研究内容为（1）lncRNA-RP11-274H2.3(LNCSRLR)结合hnRNPA2B1蛋白，上调赖氨酸羟化酶2（PLOD2）和IL-6，激活下游PI3K/AKT、MAPK等信号通路，诱导奥希替尼耐药；（2）蟾毒灵通过抑制LNCSRLR，下调PLOD2、IL-6，抑制PI3K/AKT、MAPK等逆转肺癌奥希替尼耐药。本项目首先为评估奥希替尼耐药提供了重要的分子标志物和治疗靶点；其次从非编码RNA角度研究了蟾毒灵逆转奥希替尼耐药的机制，为开发抗肿瘤中药提供新思路和理论基础。