M1  macrophages deliver CASC19  via exosomes to inhibit the proliferation and migration of colon cancer cells

Abstract

Background Here we aim to reveal the mechanism of how lncRNA CASC19 in exosomes from macrophages in the tumor microenvironment affects the proliferation and migration of colon cancer. Methods The expression levels of CASC19 and its putative target miR-410-3p were detected by reverse-transcription polymerase chain reaction (RT-qPCR).Cell proliferation and migration were evaluated by MTS and transwell assays. The characterization of exosome was conducted by western-blot, nanoSight particle tracking analysis, and electron microscope imaging. The interaction between CASC19 and miR-410-3p was detected by the pull-down assay. Results The non-contact inhibition of M1 macrophages on the proliferation of colon cancer cells is largely dependent on the CASC19 released from their exosomes. M1 exosomes successfully delivered CASC19 to colon cancer cells, exerting an inhibitory effect on cell proliferation and migration. The exosomes secreted by M1 cells with CASC19 knock down showed less inhibition on cell proliferation and migration. CASC19 exerted an inhibitory effect on colon cancer cells by sponging miR-410-3p. Conclusion CASC19 in M1 macrophages is delivered into colon cancer cells via exosomes, exerting an inhibitory effect on their proliferation and migration by sponging miR-410-3p.