Shandong Cancer Hospital and Institute, Shandong Fist Medical University and Shandong Academy of Medical Science, No 440, Jiyan Road, Ji'nan, Shandong, China.
Jinan Third People's Hospital, Shandong, China.
Hepatol Int. 2023 Aug;17(4):889-903. doi: 10.1007/s12072-023-10507-y. Epub 2023 Mar 17.
Accumulating evidence has elucidated that the interaction between cancer cells and M2 macrophages plays an important role in the tumorigenesis of hepatocellular carcinoma (HCC). However, the mechanism connecting tumor-derived exosomes, M2 polarization of macrophages, and liver metastasis remain unclear. Therefore, it is necessary to explore their influence on the tumor microenvironment of HCC.
Transmission electron microscopy, nanometer particle testing, and special biomarker analysis were utilized to characterize exosomes, while the differential expression of microRNAs was evaluated using high-throughput sequencing technology. The functions of miR-200b-3p exosomes were confirmed using in vitro and in vivo assays. The interactions between microRNAs and ZEB1 as well as cancer cells and macrophages were measured using RNA pull-down and luciferase gene reporter assays.
Using in silico analysis, we identified high levels of miR-200b-3p exosome expression in patients with HCC, particularly with relapsed HCC. We demonstrated that HCC cell-derived miR-200b-3p exosomes were internalized by M0 macrophages and induced M2 polarization by downregulating ZEB1 and upregulating interleukin-4. As a result, the JAK/STAT signaling pathway was activated in M2 macrophages, leading to increased PIM1 and VEGFα expression. These cell factors accelerated the proliferation and metastasis of HCC, resulting in a feedback loop between HCC cells and M2 macrophages.
The study illustrates that HCC cell-derived miR-200b-3p exosomes facilitate the proliferation and polarization of macrophages by modulating cytokine secretion and the JAK/STAT signaling pathway, leading to the metastasis of HCC. These findings demonstrate the existence of a novel feedback loop between cancer cells and immune cells in the tumor microenvironment, presenting a new concept in cancer research.
越来越多的证据表明，癌细胞与 M2 巨噬细胞之间的相互作用在肝细胞癌（HCC）的发生发展中起着重要作用。然而，肿瘤衍生的外泌体、巨噬细胞的 M2 极化与肝转移之间的联系机制尚不清楚。因此，有必要探讨它们对 HCC 肿瘤微环境的影响。
采用透射电子显微镜、纳米颗粒检测和特殊生物标志物分析来对 exosomes 进行表征，同时利用高通量测序技术评估 microRNAs 的差异表达。采用体外和体内实验来验证 miR-200b-3p 外泌体的功能。采用 RNA 下拉和荧光素酶基因报告实验来测量 microRNAs 与 ZEB1 以及癌细胞与巨噬细胞之间的相互作用。
通过计算机分析，我们发现 HCC 患者，尤其是复发 HCC 患者的 miR-200b-3p 外泌体表达水平较高。我们证明，HCC 细胞来源的 miR-200b-3p 外泌体被 M0 巨噬细胞内化，并通过下调 ZEB1 和上调白细胞介素-4 诱导 M2 极化。结果，M2 巨噬细胞中 JAK/STAT 信号通路被激活，导致 PIM1 和 VEGFα 的表达增加。这些细胞因子加速了 HCC 的增殖和转移，导致 HCC 细胞与 M2 巨噬细胞之间形成反馈环。
该研究表明，HCC 细胞来源的 miR-200b-3p 外泌体通过调节细胞因子分泌和 JAK/STAT 信号通路促进巨噬细胞的增殖和极化，导致 HCC 的转移。这些发现表明，在肿瘤微环境中，癌细胞与免疫细胞之间存在一种新的反馈环，为癌症研究提供了一个新概念。
