M2 Macrophage-Derived Exosomal lncRNA AFAP1-AS1 and MicroRNA-26a Affect Cell Migration and Metastasis in Esophageal Cancer
Xifeng Mi, Rongyu Xu, Shunzhong Hong, Tingting Xu, Wanfei Zhang, Ming Liu
Abstract
Exosomes from cancer cells or immune cells, carrying bio-macromolecules or long non-coding RNAs (lncRNAs), participate in tumor pathogenesis and progression by modulating the microenvironment. This study aims to explore the function of M2 macrophage-derived exosomes on the invasion and metastasis of esophageal cancer (EC) with the involvement of the lncRNA AFAP1-AS1/microRNA-26a (miR-26a)/activating transcription factor 2 (ATF2) axis. We found that lncRNA AFAP1-AS1 could specifically bind to miR-26a, thus affecting the expression of miR-26a, and ATF2 was the direct target of miR-26a. Compared with M1 macrophage-derived exosomes, M2 macrophage-derived exosomes exhibited higher AFAP1-AS1 and ATF2 expression and lower miR-26a expression. Moreover, extracellular AFAP1-AS1 could be moved to KYSE410 cells via being incorporated into M2 macrophage-derived exosomes. M2 macrophage-derived exosomes could downregulate miR-26a and promote the expression of ATF2 through high expression of AFAP1-AS1, thus promoting the migration, invasion, and lung metastasis of EC cells; M2-exosomes upregulating AFAP1-AS1 or downregulating miR-26a ameliorated this effect. In summary, M2 macrophage-derived exosomes transferred lncRNA AFAP1-AS1 to downregulate miR-26a and upregulate ATF2, thus promoting the invasion and metastasis of EC. Targeting M2 macrophages and the lncRNA AFAP1-AS1/miR-26a/ATF2 signaling axis represents a potential therapeutic strategy for EC.