外泌体传递miR-425-3p调控Akt/mTOR通路诱导非小细胞肺癌顺铂耐药的机制研究

Cisplatin resistance is one of the main causes of disease progression in NSCLC patients. It is reported that exosomes can induce resistance by transferring miRNAs and autophagy as a protective mechanism after DNA injury, which is an important factor for cisplatin resistance. However, the effect and mechanism of exosomal miRNAs on autophagy and NSCLC cisplatin resistance are not yet clear. In our previous study, we found that miR-425-3p was highly expressed in cisplatin resistant patients, targeted AKT1, inhibited Akt/mTOR pathway and promoted autophagy of NSCLC. Therefore, it is speculated that cisplatin low sensitive NSCLC cells release the exosomes rich in miR-425-3p, enhance the autophagy activity of the receptor cells and promote the resistance of NSCLC cisplatin. This project is from the three aspects of cell lines, animal models and clinical samples. We aim to clarify the effect by exosomal miR-425-3p down-regulation of AKT1 on NSCLC cisplatin resistance, obtain specific mechanisms of the inhibition of Akt/mTOR signaling pathway to promote autophagy and finally reveal the molecular mechanism of exosomal miR-425-3p inducing autophagy to enhance cisplatin resistance in NSCLC through Akt/mTOR signaling pathway. It may provide potential novel targets for treatment of clinical NSCLC patients.

NSCLC顺铂耐药是患者疾病进展的主要原因之一。研究报道外泌体通过转运miRNAs诱导耐药而自噬作为细胞DNA损伤后的保护机制，是顺铂耐药的重要因素。然而外泌体miRNAs对自噬的作用及对NSCLC顺铂耐药的影响和机制尚不明确。我们前期研究发现miR-425-3p在顺铂耐药病人中高表达，靶向AKT1，抑制Akt/mTOR通路，促进NSCLC自噬。因此推测：顺铂低敏感NSCLC细胞释放富含miR-425-3p的外泌体，增强受体细胞的自噬活性，促进NSCLC顺铂耐药。本项目拟从细胞系、动物模型、临床标本三个层面阐明外泌体miR-425-3p抑制AKT1对NSCLC顺铂耐药性的影响；获得其下调Akt/mTOR信号通路促进自噬的具体机制；最终揭示外泌体miR-425-3p调控Akt/mTOR信号通路促进自噬诱导NSCLC顺铂耐药的分子机制，为临床NSCLC患者个体化治疗提供新的理论依据和治疗策略。

NSCLC顺铂耐药是患者疾病进展的主要原因之一。研究报道外泌体通过转运miRNAs诱导耐药而自噬作为细胞DNA损伤后的保护机制，是顺铂耐药的重要因素。然而外泌体miRNAs对自噬的作用及对NSCLC顺铂耐药的影响和机制尚不明确。我们前期研究发现miR-425-3p在顺铂耐药病人中高表达，靶向AKT1，抑制Akt/mTOR通路，促进NSCLC自噬。本项目通过功能获得和功能丧失为主的实验阐明了miR-425-3p的反应性调节作用。通过细胞共培养发现顺铂治疗后或顺铂耐药NSCLC 细胞释放富含miR-425-3p的外泌体，增强受体细胞的自噬活性，促进NSCLC顺铂耐药。进一步通过生物信息学、芯片和荧光素酶报告分析，发现顺铂诱导c-Myc直接结合miR-425-3p启动子并反式激活其表达。外源性miR-425-3p通过靶向AKT1促进受体细胞的自噬激活，最终导致化疗耐药。并在以铂为基础的化疗过程中，通过qRT-PCR在NSCLC患者成对血清样本中验证,循环外泌体miR-425-3p的表达呈上升趋势。这为临床NSCLC患者个体化治疗提供新的理论依据和治疗策略。