Acidic Microenvironment Up-Regulates Exosomal miR-21 and miR-10b in Early-Stage Hepatocellular Carcinoma to Promote Cancer Cell Proliferation and Metastasis
Acidic Microenvironment Up-Regulates Exosomal miR-21 and miR-10b in Early-Stage Hepatocellular Carcinoma to Promote Cancer Cell Proliferation and Metastasis
复制标题
酸性微环境上调早期肝细胞癌中的外泌体 miR-21 和 miR-10b，促进癌细胞增殖和转移
DOI：
10.7150/thno.30958
复制
发表时间：
2019-01-01
期刊：
影响因子：
12.4
通讯作者：
Xie, Dan
中科院分区：
文献类型：
--
作者：
Tian, Xiao-Peng;Wang, Chen-Yuan;Xie, Dan
原理：全世界肝细胞癌的发病率正在上升。据预测，近一半的早期肝细胞癌（E-HCC）患者会复发。pH失调是E-HCC的标志，与预后不良相关。酸性微环境已显示促进外泌体的释放，外泌体是被认为与肿瘤进展、复发和转移相关的细胞间通讯者的膜囊泡。因此，本研究旨在筛选酸性微环境诱导的可能调控E-HCC进展的exosomes，并探讨其调控E-HCC进展的机制和临床意义。侵袭和划痕实验检测HCC细胞的迁移和侵袭。采用免疫印迹和免疫荧光技术检测肝癌细胞上皮间质转化（EMT）。染色质免疫沉淀法（ChIP）检测HIF-1a和HIF-2a与miR-21和miR-10 b启动子区的结合情况。来自在酸性培养基中培养的HCC细胞的外泌体可以促进受体HCC细胞的细胞增殖、迁移和侵袭。我们鉴定了miR-21和miR-10 b是酸性HCC来源的外泌体中最重要的功能性miRNA。此外，酸性微环境触发了HIF-1a和HIF-2a的激活，并刺激了外泌体miR-21和miR-10 b的表达，大大促进了体内和体外肝癌细胞的增殖、迁移和侵袭。在E-HCC患者中，血清外泌体miR-21和miR-10 b水平与晚期肿瘤分期以及HIF-1a和HIF-2a表达相关，并且是E-HCC患者无病生存的独立预后因素。结论：酸性微环境诱导的外泌体miR-21和miR-10 b的表达促进了肝癌细胞的增殖和转移，可作为肝癌预后的分子标志物和治疗靶点。
Rationale: The incidence of hepatocellular carcinoma is rising worldwide. It is predicted that nearly half of the early-stage hepatocellular carcinoma (E-HCC) patients will develop recurrence. Dysregulated pH, a hallmark of E-HCC, is correlated with poor prognosis. The acidic microenvironment has been shown to promote the release of exosomes, the membrane vesicles recognized as intercellular communicators associated with tumor progression, recurrence, and metastasis. We, therefore, aimed to identify exosomes induced by acidic microenvironment that may regulate E-HCC progression and to explore their mechanisms and clinical significance in E-HCCs.Methods: miRNA microarray analysis and LASSO logistic statistic model were used to identify the main functional exosomal miRNAs. Invasion and scratch assays were performed to examine the migration and invasion of HCC cells. Immunoblotting and immunofluorescence were employed to detect the epithelial-to-mesenchymal transition (EMT) in HCC cells. Chromatin immunoprecipitation (ChIP) was used to analyze the binding of HIF-1a and HIF-2a to promoter regions of miR-21 and miR-10b.Results: The acidic microenvironment in HCC was correlated with poor prognosis of patients. Exosomes from HCC cells cultured in the acidic medium could promote cell proliferation, migration, and invasion of recipient HCC cells. We identified miR-21 and miR-10b as the most important functional miRNAs in acidic HCC-derived exosomes. Also, the acidic microenvironment triggered the activation of HIF-1a and HIF-2a and stimulated exosomal miR-21 and miR-10b expression substantially promoting HCC cell proliferation, migration, and invasion both in vivo and in vitro. In E-HCC patients, serum exosomal miR-21 and miR-10b levels were associated with advanced tumor stage and HIF-1a and HIF-2a expression and were independent prognostic factors for disease-free survival of E-HCC patients. Most importantly, we developed a nano-drug to target exosomal miR-21 and/or miR-10b and examined its therapeutic effects against HCC in vivo.Conclusion: Our findings suggested that the exosomal miR-21 and miR-10b induced by acidic microenvironment in HCC promote cancer cell proliferation and metastasis and may serve as prognostic molecular markers and therapeutic targets for HCC.