Cancer-associated fibroblasts (CAFs) play supporting roles in tumor progression by releasing microvesicles that transmit oncogenic cargoes. Indeed, extracellular vesicles (EVs) have emerged as important vehicles to deliver proteins, messenger RNAs (mRNAs), and microRNAs (miRs) between cells. In this study, we aimed to outline the role and function of CAFs-derived EVs carrying miR-1-3p in breast cancer. We first experimentally determined downregulated miR-1-3p in breast cancer tissues. EVs were isolated from CAFs extracted from breast cancer tissues, which showed downregulated miR-1-3p expression relative to EVs derived from normal fibroblasts (NFs). In a co-culture system, miR-1-3p cargo was transported into breast cancer cells via CAF-derived EVs. In gain-of-function experiments, the elevation of miR-1-3p in breast cancer cells inhibited cell viability, invasion, migration, and epithelial-to-mesenchymal transition, and suppressed tumor formation and metastasis. Furthermore, EVs derived from CAFs transfected with miR-1-3p mimic were more effective in transferring miR-1-3p to suppress cancer progression and metastasis. Krüppel-like zinc-finger protein Gli-similar 1 (GLIS1) was predicted to be a putative target of miR-1-3p, which was subsequently confirmed by dual-luciferase reporter assay. We then demonstrated that overexpression of GLIS1 neutralized the effects of miR-1-3 on the development of breast cancer in vitro. These findings shed light on the underlying mechanism by which CAFs-derived EVs carrying miR-1-3p mediate the progression and metastasis of breast cancer, and highlight the potential of miR-1-3p shuttled by CAFs-derived EVs serving as a therapeutic target for breast cancer.

癌症相关成纤维细胞 (CAF) 通过释放微泡来传输致癌物质，从而在肿瘤进展中发挥支持作用。事实上，细胞外囊泡 (EV) 已成为在细胞之间传递蛋白质、信使 RNA (mRNA) 和 microRNA (miR) 的重要载体。在这项研究中，我们旨在概述携带 miR-1-3p 的 CAF 衍生的 EV 在乳腺癌中的作用和功能。我们首先通过实验确定了乳腺癌组织中下调的 miR-1-3p。EVs 是从从乳腺癌组织中提取的 CAFs 中分离出来的，相对于来自正常成纤维细胞 (NFs) 的 EVs，其 miR-1-3p 表达下调。在共培养系统中，miR-1-3p 货物通过 CAF 衍生的 EV 转运到乳腺癌细胞中。在功能增益实验中，乳腺癌细胞中 miR-1-3p 的升高抑制了细胞活力、侵袭、迁移和上皮间质转化，并抑制了肿瘤的形成和转移。此外，转染 miR-1-3p 模拟物的 CAF 衍生的 EV 在转移 miR-1-3p 以抑制癌症进展和转移方面更有效。Krüppel 样锌指蛋白 Gli-similar 1 (GLIS1) 被预测为 miR-1-3p 的推定靶标，随后通过双荧光素酶报告基因测定证实了这一点。然后我们证明了 GLIS1 的过表达中和了 miR-1-3 对体外乳腺癌发展的影响。这些发现揭示了携带 miR-1-3p 的 CAF 衍生的 EV 介导乳腺癌进展和转移的潜在机制，