Colorectal cancer (CRC) is the most common
malignancy in the digestive system, and
tumor metastasis is the main cause of death in clinical patients with CRC. It has been shown that exosomes promote phenotypic changes in macrophages and
tumor metastasis in the CRC tumor microenvironment. In this study, we used
miRNA-seq technology to screen out the highly expressed miR-372-5p among the
miRNAs differentially expressed in plasma exosomes of clinical CRC patients. It was found that miR-372-5p highly expressed in HCT116 exosomes could be phagocytosed by macrophages and promote their polarization into M2 macrophages by regulating the PTEN/AKT pathway. Meanwhile, co-culture of CRC cells with
conditioned medium (CM) of macrophages enhanced the EMT, stemness and
metastasis of CRC cells. Mechanistically, CRC cells exosome-derived miR-372-5p induced polarized M2 macrophages to secrete
chemokine C-X-C-Motif Ligand 12 (CXCL12), which activated the WNT/β-
catenin pathway to promote the EMT, stemness and metastatic ability of CRC cells. In summary, this study elucidated the molecular mechanism of exosomal miR-372-5p promoting
metastasis and stemness in CRC, which may provide new therapeutic targets for CRC
metastasis and prognosis assessment.