Exosomal miR-183-5p promotes angiogenesis in colorectal cancer by regulation of FOXO1

Exosomes play important roles in proliferation and microenvironment modulation of many types of cancers, including colorectal cancer (CRC). However, the inhibitory effect of CRC cells-derived exosomes in angiogenesis has not been fully discussed. In this study, the roles of microRNA-183-5p (miR-183-5p) in abundant in exosomes secreted from the CRC cells were investigated. Initially, microarray analysis was employed to determine the differentially expressed miRNAs. Exosomes isolated from CRC cells were co-cultured with HMEC-1 cells to explore the role of exosomes in angiogenesis. Further, the effects of CRC cell-derived exosomal miR-183-5p on proliferation, invasion and tube formation abilities of HMEC-1 cells were assessed. The preventative effect of exosomal miR-183-5p in vivo was measured in nude mice. Initially, it was found that FOXO1 was downregulated while miR-183-5p was upregulated in CRC. Additionally, the inhibition of miR-183-5p was suggested to suppress proliferation, invasion and tube formation abilities of HMEC-1 cells through upregulating FOXO1. Then, in vitro assays demonstrated that CRC cell-derived exosomes overexpressing miR-183-5p contributed to an enhanced proliferation, invasion and tube formation abilities of HMEC-1 cells. Furthermore, in vivo experiments confirmed the tumor-promotive effects of CRC cell-derived exosomal miR-183-5p. Collectively, our study demonstrates that the CRC cell-derived exosomes overexpressing miR-183-5p aggravates CRC through the regulation of FOXO1. Exosomes overexpressing miR-183-5p might be a potential treatment biomarker for CRC.