肝癌来源Exosomes调节巨噬细胞M2型极化的机制研究

Tumor cells can cause macrophages polarization ranging within the spectrum of M1 (classical) to M2 (alternative) activation by different ways. Tumor cells-derived exosomes are important facilitators of intercellular communication by transporting contents, such as protein, mRNA, and microRNA, between neighboring cells, such as tumor cells and macrophages in the tumor microenvironment. Our previous studies showed that macrophages were not polarized to the typical M1 or M2 macrophage by co-culturing with the hepatocytes in a transwell co-culture system, but macrophages obviously showed the tendency activation to the M2 macrophage by presence of hepatoma cells-derived exosomes. The results suggest that hepatoma cells-derived exosomes in the microenvironment are the pivotal "trigger" to the polarization of macrophages subtype. However, the key regulators and effectors of the exosomes induced M1 and M2 macrophage polarization pathway remain unclear so far. The purpose of current study is to investigate the key content of exosomes-mediated cellular communication between human hepatoma cells and macrophages by microRNA array，qPCR and protein mass spectrometry, especially analyzing the correlation between exosomes and macrophages subtype in clinical specimens. To identify the signaling molecules related to M2 subtype, RNA-IP or IP is designed, the lentiviral vector is used to get the ectopic overexpression in macrophages. Further, the key regulators of the M1 and M2 macrophage effectors in polarization pathway and its role in hepatocellular carcinoma development are illuminated in nude mice. Based on these results, novel therapies targeting selective manipulation of tumor cell-derived exosomes content may be very promising.

肿瘤细胞可通过多种方式影响巨噬细胞在M1和M2两个亚型之间发生动态改变，其中癌细胞来源的exosomes是介导细胞间信息传递的重要介质。我们前期研究发现肝细胞与巨噬细胞共培养未致后者向典型M1或M2极化，但肝癌细胞来源的exosomes致巨噬细胞M2极化趋势明显。提示癌细胞来源的exosomes可能是致巨噬细胞M2极化的 “导火索”，但其中关键组分及机制尚不清楚。本研究拟通过miRNAarray、 qPCR和蛋白质谱等手段寻找致巨噬细胞M2极化的exosomes组分，同时分析临床标本中该组分的表达与巨噬细胞亚型的相关性；进一步利用慢病毒载体在巨噬细胞内过表达该组分，通过RNA-IP或IP筛选出巨噬细胞亚型极化的关键信号通路分子；并在此基础上探讨裸鼠致瘤模型中exosomes与体内巨噬细胞亚型极化的相关性，进而阐明其诱导巨噬细胞M2型极化的调控机制。为建立肝癌治疗的新模式奠定理论和实验基础。