外泌体 microRNA-107 通过 HMGA2/mTOR/P-gp 通路逆转胃癌细胞的化疗耐药性。
Exosomal microRNA-107 reverses chemotherapeutic drug resistance of gastric cancer cells through HMGA2/mTOR/P-gp pathway.
机构信息
Henan University of Chinese Medicine, 156 Jinshui East Road, Zhengzhou, 450046, China.
School of Life and Health Sciences, The Chinese University of Hong Kong (Shenzhen), 2001 Longxiang Ave, Shenzhen, 518172, China.
出版信息
BMC Cancer. 2021 Dec 2;21(1):1290. doi: 10.1186/s12885-021-09020-y.
BACKGROUND
RNA cargo in exosomes, especially microRNAs (miRNAs), play an important role in the chemotherapy drug resistance of human cancers. However, the role and mechanism of exosomal miR-107 on multidrug resistance of gastric cancer cells was still not clear. In this study, we sought to explore whether exosomal miR-107 could reverse the resistance of gastric cancer cells to the chemotherapy drugs.
METHODS
We extracted exosomes from sensitive (SGC-7901, MGC-803) and resistant (SGC-7901/5-FU) gastric cancer cells by ultracentrifugation and the isolated exosomes were identified using transmission electron microscopy (TEM) and dynamic light scattering analysis (DLS). The expression of miR-107 and high mobility group A2 (HMGA2) were detected by real-time quantitative PCR (RT-qPCR). MTT assay was used to investigate the effect of exosomes on gastric cancer cells growth in vitro. The uptake of exosomes by recipient cells were observed using a fluorescence microscope. The predicted target relationship between miR-107 and HMGA2 was verified by gauss-luciferase reporter assay. The expression of HMGA2, p-mTOR/mTOR, P-gp and other exosomal indicated marker proteins was detected by western blot.
RESULTS
Our results indicated that the isolated exosomes were typically cup-like lipid bilayer membranes structure. SGC-7901/5-FU cells were cross-resistant to chemotherapy drug cisplatin (CDDP), and the sensitive cells-secreted exosomes drastically reversed the resistance of the resistant GC cells to the chemotherapeutic drugs, which was verified by exosomal inhibitor GW4896. Mechanistically, the reversal effect was mainly mediated by exosome-secreted miR-107 through downregulating the expression of target molecular HMGA2 and inhibiting HMGA2/mTOR/P-gp pathway, which were supported by results from luciferase reporter assay and rescue assay.
CONCLUSIONS
These findings demonstrated that exosome-transmitted miR-107 significantly enhanced the sensitivity of resistant gastric cancer cells to chemotherapeutic agents by mediating the HMGA2/mTOR/P-gp axis and exosomal miR-107 may be a novel target in gastric cancers treatment.
背景
外泌体中的 RNA 货物，特别是 microRNAs（miRNAs），在人类癌症的化疗药物耐药性中发挥着重要作用。然而，外泌体 miR-107 对胃癌细胞多药耐药性的作用和机制尚不清楚。在这项研究中，我们试图探讨外泌体 miR-107 是否可以逆转胃癌细胞对化疗药物的耐药性。
方法
我们通过超速离心从敏感（SGC-7901、MGC-803）和耐药（SGC-7901/5-FU）胃癌细胞中提取外泌体，并通过透射电子显微镜（TEM）和动态光散射分析（DLS）鉴定分离的外泌体。采用实时定量 PCR（RT-qPCR）检测 miR-107 和高迁移率族蛋白 A2（HMGA2）的表达。MTT 法检测外泌体对体外胃癌细胞生长的影响。用荧光显微镜观察受体细胞对外泌体的摄取。用高斯-荧光素酶报告基因检测验证 miR-107 与 HMGA2 之间的预测靶关系。用 Western blot 检测 HMGA2、p-mTOR/mTOR、P-gp 等外泌体指示标记蛋白的表达。
结果
结果表明，分离的外泌体具有典型的杯状脂质双层膜结构。SGC-7901/5-FU 细胞对化疗药物顺铂（CDDP）具有交叉耐药性，而敏感细胞分泌的外泌体则明显逆转了耐药 GC 细胞对化疗药物的耐药性，这一结果通过外泌体抑制剂 GW4896 得到了验证。机制上，这种逆转作用主要是通过外泌体分泌的 miR-107 介导的，通过下调靶分子 HMGA2 的表达并抑制 HMGA2/mTOR/P-gp 通路来实现，这一结果得到了荧光素酶报告基因检测和挽救实验的支持。
结论
这些发现表明，外泌体传递的 miR-107 通过介导 HMGA2/mTOR/P-gp 轴显著增强了耐药胃癌细胞对化疗药物的敏感性，外泌体 miR-107 可能成为胃癌治疗的新靶点。
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