Cancer-associated fibroblast-released extracellular vesicles carrying miR-199a-5p induces the progression of​ gastric cancer through regulation of FKBP5-mediated AKT1/mTORC1 signaling pathway

Accumulating evidence has unfolded the significance of extracellular vesicles (EVs) in diseases and cancers. Here, we attempted to discuss the role of cancer-associated fibroblasts (CAFs)-derived EVs containing miR-199a-5p in gastric tumorigenesis. Upregulated miR-199a-5p was first identified in cancer cells. Then, we selected CAFs for isolation of EVs which were co-cultured with AGS cells. We observed successful delivery of miR-199a-5p via CAF-derived EVs. Besides, miR-199a-5p promoted malignant properties of AGS cells. Moreover, miR-199a-5p downregulated FKBP5, leading to upregulated phosphorylation level of AKT1, which promoted the malignant phenotypes of AGS cells by activating mammalian target of rapamycin complex 1(mTORC1). Exosomal miR-199a-5p from CAFs promoted gastric tumorigenesis <i>in vivo</i>. Our findings point toward the critical role of CAFs-derived EVs carrying miR-199a-5p in gastric cancer progression.