Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center of Cancer Medicine, Guangzhou, China.
Department of Reproductive Medicine, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China.
Theranostics. 2019 Mar 16;9(7):1965-1979. doi: 10.7150/thno.30958. eCollection 2019.
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. 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-1α and HIF-2α to promoter regions of miR-21 and miR-10b. 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-1α and HIF-2α and stimulated exosomal miR-21 and miR-10b expression substantially promoting HCC cell proliferation, migration, and invasion both and . In E-HCC patients, serum exosomal miR-21 and miR-10b levels were associated with advanced tumor stage and HIF-1α and HIF-2α 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 . 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.
肝细胞癌的发病率在全球范围内呈上升趋势。据预测，近半数早期肝细胞癌（E-HCC）患者将出现复发。E-HCC 的标志之一是 pH 值失调，与预后不良相关。酸性微环境已被证明可促进外泌体的释放，外泌体是公认的与肿瘤进展、复发和转移相关的细胞间通讯的膜囊泡。因此，我们旨在鉴定可能调节 E-HCC 进展的酸性微环境诱导的外泌体，并探讨其在 E-HCC 中的机制和临床意义。
miRNA 微阵列分析和 LASSO 逻辑统计模型用于鉴定主要的功能性外泌体 miRNA。侵袭和划痕实验用于检测 HCC 细胞的迁移和侵袭。免疫印迹和免疫荧光用于检测 HCC 细胞的上皮间质转化（EMT）。染色质免疫沉淀（ChIP）用于分析 HIF-1α 和 HIF-2α 与 miR-21 和 miR-10b 启动子区域的结合。
HCC 中的酸性微环境与患者的不良预后相关。在酸性培养基中培养的 HCC 细胞的外泌体可促进受者 HCC 细胞的增殖、迁移和侵袭。我们鉴定出 miR-21 和 miR-10b 为酸性 HCC 衍生外泌体中最重要的功能性 miRNA。此外，酸性微环境触发了 HIF-1α 和 HIF-2α 的激活，并显著刺激了外泌体 miR-21 和 miR-10b 的表达，从而促进了 HCC 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-10b 水平与肿瘤晚期、HIF-1α 和 HIF-2α 表达相关，是 E-HCC 患者无病生存的独立预后因素。最重要的是，我们开发了一种针对外泌体 miR-21 和/或 miR-10b 的纳米药物，并研究了其对 HCC 的治疗效果。
我们的研究结果表明，HCC 酸性微环境诱导的外泌体 miR-21 和 miR-10b 可促进癌细胞增殖和转移，可能作为 HCC 的预后分子标志物和治疗靶点。
