Extracellular ubiquitin promotes hepatoma metastasis by mediating M2 macrophage polarization via the activation of the CXCR4/ERK signaling pathway
Extracellular ubiquitin promotes hepatoma metastasis by mediating M2 macrophage polarization via the activation of the CXCR4/ERK signaling pathway
复制标题
细胞外泛素通过激活CXCR4/ERK信号通路介导M2巨噬细胞极化来促进肝癌转移。
DOI：
10.21037/atm-20-1054
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发表时间：
2020-08-01
影响因子：
--
通讯作者：
Xia, Rong
中科院分区：
文献类型：
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作者：
Cai, Jiajing;Zhang, Qi;Xia, Rong
背景：储存的红细胞（RBC）输注已被证明可增加癌症复发的风险。然而，其潜在机制尚不清楚。在我们的实验室，我们已经证明了老化红细胞释放的细胞外泛素（eUb）可以促进黑色素瘤小鼠模型中的肿瘤转移。本研究旨在证实eUb对肝细胞癌（HCC）的促瘤作用，并探讨其相关的免疫调节机制。方法：收集40例肝癌组织标本及相应的邻近非肿瘤及正常肝组织。本研究采用2个人肝癌细胞系（MHCC-97H和HepG2.2.15）、1个鼠肝癌细胞系（Nepal-6）和1个人单核细胞细胞系（THP-1）。用Transwell插入物开始肝癌细胞与巨噬细胞的共培养。采用Transwell法和创面愈合法检测体外细胞迁移，荧光素酶法和H&E染色法检测体内肿瘤转移。采用流式细胞术、免疫荧光、ELISA、qPCR和Western blot检测巨噬细胞极化。Western blot检测蛋白表达，免疫沉淀法证实Ub与CXCR4 （CXC趋化因子受体4型）的相互作用。结果：Ub和CXCR4在HCC组织中显著上调，且两者呈正相关。在体外，肝癌细胞的迁移不受eUb的直接影响，但与经eUb预处理的巨噬细胞共培养后，肝癌细胞的转移能力增强。同时，eUb在体内促进肝癌细胞在肺内的转移，增加荷瘤小鼠肺组织和外周血中M2巨噬细胞的比例。此外，eub诱导的M2巨噬细胞极化与CXCR4/ERK（细胞外调节蛋白激酶）信号通路的激活有关。结论：细胞外泛素通过激活CXCR4/ERK信号通路，通过M2巨噬细胞极化促进肝癌转移，提示HCC患者的治疗需要个性化输血策略。在储存的红细胞单位中和Ub可以减少由储存的红细胞输血引起的有害临床结果。
Background: Stored red blood cell (RBC) transfusion has been shown to enhance the risk of cancer recurrence. However, the underlying mechanism remains unknown. At our lab, we have demonstrated that the extracellular ubiquitin (eUb) released by aged RBCs could promote tumor metastasis in a melanoma mouse model. This study aimed to confirm the pro-tumor effect of eUb on hepatocellular carcinoma (HCC) and explore the related immunoregulatory mechanisms.Methods: Forty HCC tissue specimens and the corresponding adjacent nontumor and normal liver tissues were collected. Two human hepatoma cell lines (MHCC-97H and HepG2.2.15), one murine hepatoma cell line (Nepal-6), and one human monocyte cell line (THP-1) were adopted in this study. The coculture of hepatoma cells with macrophages was initiated with Transwell inserts. Cell migration in vitro was detected by Transwell and wound-healing assays, while in vivo tumor metastasis was measured by luciferase assay and H&E staining. Macrophage polarization was measured by flow cytometry, immunofluorescence, ELISA, qPCR, and Western blot. Protein expression was detected by Western blot, and immunoprecipitation was used to confirm the interaction between Ub and CXCR4 (CXC chemokine receptor type 4).Results: Ub and CXCR4 were significantly upregulated in HCC tissues, and a positive correlation existed between them. In vitro, the migration of hepatoma cells was not affected by eUb directly, but their metastatic abilities were enhanced after coculture with the macrophages pretreated with eUb. Meanwhile, eUb promoted hepatoma cell metastasis in the lung in vivo and increased the ratio of M2 macrophages in the lung tissues and peripheral blood of tumor-bearing mice. Furthermore, the eUb-induced M2 macrophage polarization was related to the activation of the CXCR4/ERK (extracellular regulated protein kinase) signaling pathway.Conclusions: Extracellular ubiquitin promoted hepatoma metastasis through M2 macrophage polarization via the activation of the CXCR4/ERK signaling pathway, indicating that a personalized transfusion strategy is needed for the treatment of HCC patients. Neutralizing Ub in stored RBC units could lessen the detrimental clinical outcomes induced by the transfusion of stored RBCs.