Department of Hepatobiliary Surgery, The First Hospital of China Medical University, Shenyang, 110001, PR China.
Department of Gynecology, The First Hospital of China Medical University, Shenyang, 110001, PR China.
Exp Cell Res. 2020 Sep 15;394(2):112113. doi: 10.1016/j.yexcr.2020.112113. Epub 2020 May 28.
Accumulating evidence indicates that cancer-associated fibroblasts (CAFs) play a crucial role in endometrial cancer (EC) pathogenesis. The present study investigated the clinical significance and biological function of extracellular vesicle (EV) encapsulated miR-320a released from CAFs in EC. EC-related microarray data was obtained from the GSE25405 database and differential analysis was performed. Expression of miR-320a in CAFs and normal endometrial fibroblasts (NFs) as well as CAF-delivered EVs was detected; also, delivery of miR-320a from CAFs to EC cells was observed. In addition we confirmed that miR-320a targets HIF1α via a dual-luciferase reporter assay. Phenotypic analysis was used to study the functional significance of EV delivered miR-320a and its downstream effects. miR-320a was found to have low expression in EC cells and tissues. CAF-secreted EVs were successfully isolated and miR-320a was found also be expressed at low levels in these EVs. Finally, we found direct transfer of CAF-secreted exosomal miR-320a to EC cells, which inhibited their proliferation. Mechanistically, we found this is due to downregulation of HIF1α by miR-320a, which led to lowered VEGFA expression in vitro. Accordingly, we overexpressed HIF1α also showed that the inhibitory effect of miR-320a overexpression in EC cells could be reversed. These results point to CAF-derived EVs carrying overexpressed miR-320a as a novel direction for therapeutic strategies for EC.
越来越多的证据表明，癌症相关成纤维细胞（CAFs）在子宫内膜癌（EC）发病机制中发挥着关键作用。本研究探讨了源自 CAFs 的细胞外囊泡（EV）包裹的 miR-320a 在 EC 中的临床意义和生物学功能。从 GSE25405 数据库中获得与 EC 相关的微阵列数据，并进行差异分析。检测了 CAFs 和正常子宫内膜成纤维细胞（NFs）以及 CAF 分泌的 EV 中 miR-320a 的表达；还观察了 CAFs 向 EC 细胞传递 miR-320a 的情况。此外，我们通过双荧光素酶报告基因检测证实 miR-320a 靶向 HIF1α。通过表型分析研究了 EV 传递的 miR-320a 的功能意义及其下游效应。发现 miR-320a 在 EC 细胞和组织中的表达水平较低。成功分离了 CAF 分泌的 EV，并发现这些 EV 中也低表达 miR-320a。最后，我们发现 CAF 分泌的细胞外体 miR-320a 直接转移到 EC 细胞中，抑制了它们的增殖。从机制上讲，我们发现这是由于 miR-320a 下调了 HIF1α，导致体外 VEGFA 表达降低。因此，我们过表达 HIF1α 也表明 miR-320a 过表达对 EC 细胞的抑制作用可以被逆转。这些结果表明，CAF 衍生的 EV 携带过表达的 miR-320a 是 EC 治疗策略的一个新方向。
