Department of Pancreatic Surgery, Renmin Hospital of Wuhan University, 238 Jiefang Road, Wuhan, 430060, Hubei, China.
Cell Biol Toxicol. 2022 Aug;38(4):577-590. doi: 10.1007/s10565-021-09597-x. Epub 2021 Mar 17.
Given the fact that tumor-associated macrophage-derived extracellular vesicles (EVs) are attributable to tumor aggressiveness, this research intends to decode the mechanism of M2 macrophage-derived EVs in the differentiation and activities of pancreatic cancer (PaCa) stem cells via delivering microRNA (miR)-21-5p.
Polarized M2 macrophages were induced, from which EVs were collected and identified. miR-21-5p expression in M2 macrophage-derived EVs was tested. After cell sorting, CD24CD44EpCAM stem cells were co-cultured with M2 macrophages, in which miR-21-5p was upregulated or downregulated. The effects of M2 macrophage-derived EVs and miR-21-5p on Nanog/octamer-binding transcription factor 4 (Oct4) expression, sphere formation, colony formation, invasion and migration capacities, apoptosis, and in vivo tumorigenic ability were examined. Krüppel-like factor 3 (KLF3) expression and its interaction with miR-21-5p were determined.
M2 macrophage-derived EVs promoted PaCa stem cell differentiation and activities. miR-21a-5p was upregulated in M2 macrophage-derived EVs. miR-21a-5p downregulation in M2 macrophage-derived EVs inhibited Nanog/Oct4 expression and impaired sphere-forming, colony-forming, invasion, migration, and anti-apoptosis abilities of PaCa stem cells in vitro and tumorigenic ability in vivo. miR-21-5p targeted KLF3 to mediate the differentiation and activities of PaCa stem cells, and KLF3 was downregulated in PaCa stem cells.
This work explains that M2 macrophage-derived exosomal miR-21a-5p stimulates differentiation and activity of PaCa stem cells via targeting KLF3, paving a novel way for attenuating PaCa stemness.
鉴于肿瘤相关巨噬细胞衍生的细胞外囊泡（EVs）与肿瘤侵袭性有关，本研究旨在通过递送 microRNA（miR）-21-5p 来解码 M2 巨噬细胞衍生的 EV 在胰腺癌细胞（PaCa）干细胞分化和活性中的作用机制。
诱导极化的 M2 巨噬细胞，从中收集和鉴定 EV。检测 M2 巨噬细胞衍生 EV 中的 miR-21-5p 表达。细胞分选后，将 CD24CD44EpCAM 干细胞与 M2 巨噬细胞共培养，上调或下调 miR-21-5p。检测 M2 巨噬细胞衍生 EV 和 miR-21-5p 对 Nanog/Octamer-binding transcription factor 4（Oct4）表达、球体形成、集落形成、侵袭和迁移能力、凋亡以及体内致瘤能力的影响。确定 Krüppel-like factor 3（KLF3）的表达及其与 miR-21-5p 的相互作用。
M2 巨噬细胞衍生的 EV 促进了 PaCa 干细胞的分化和活性。M2 巨噬细胞衍生的 EV 中 miR-21a-5p 上调。M2 巨噬细胞衍生 EV 中 miR-21a-5p 的下调抑制了 Nanog/Oct4 的表达，并损害了 PaCa 干细胞在体外的球体形成、集落形成、侵袭、迁移和抗凋亡能力以及体内致瘤能力。miR-21-5p 通过靶向 KLF3 介导 PaCa 干细胞的分化和活性，并且 KLF3 在 PaCa 干细胞中下调。
本研究表明，M2 巨噬细胞衍生的外泌体 miR-21a-5p 通过靶向 KLF3 刺激 PaCa 干细胞的分化和活性，为减弱 PaCa 干细胞特性开辟了新途径。
