Macrophage-derived exosomes regulate gastric cancer cell oxaliplatin resistance by wrapping circ 0008253

Oxaliplatin (OXA) is a first-line chemotherapy drug for gastric cancer. We aimed to investigate the effect of circ 0008253, contained in M2 polarized macrophage-derived exosomes, on OXA resistance of gastric carcinoma cells. Flow cytometry was performed to detect the differentiation of macrophages and cell apoptosis. Cell Counting Kit-8 assay was conducted to examine the cell viability. Transmission electron microscopy, Nanoparticle Tracking Analysis, Western bolt, and Immunofluorescence were carried out. Cell proliferation was detected with a colony formation experiment. Levels of CD206, Arg1, IL-10, and TGF-β were increased in M2 polarized macrophages. Cell viability was decreased gradually with the increase of time and OXA concentration. Apoptosis of gastric carcinoma cells was decreased after co-culture with M2-polarized macrophages. Exosomes isolated from M2-polarized macrophages (M2-Exos) could be co-located with gastric carcinoma cells. M2-Exos enhanced drug resistance, reduced apoptosis and OXA resistance. Bioinformatics analysis showed that circ 0008253 could be transferred from M2-Exos to gastric carcinoma cells. Overexpressing circ 0008253 increased cell viability, tumor size, and ABCG2 levels, decreased OXA sensitivity. Circ 0008253, contained in M2-Exos, was directly transferred from tumor-associated macrophage to gastric carcinoma cells, finally enhancing OXA resistance.