Investigation of the effects of macrophage-derived exosomes on glioblastoma cellular behaviours in molecular level

In this study, it was aimed to investigate the differences that arise from M0, M1, and M2 polarized macrophage-derived exosomes at the molecular level in glioblastoma cells. Exosomes were isolated from polarized macrophage cells and their nanostructures were determined by TEM and the amount of protein was quantitatively determined by BCA assay. Co-culture systems were established to culture M0, M1, and M2 macrophages with U87 glioblastoma cells and to investigate the indirect effect of exosomes. Subsequently, exosomes were induced directly into U87 cells and direct effects were evaluated. An optimization process was carried out to prove the hypothesis in co-culture experiments. For the established exosomal system, two different concentrations of exosomes (10 and 100 g/mL) were tested and the high concentration (100 g/mL) was optimized for futher experiments. It was confirmed by analyzes that the macrophage phenotype affects the aggressiveness of glioblastoma cells and cancer progression. It was confirmed by live/dead test and XTT test that macrophage exosomes in high concentration do not have negative effect on U87 cells in terms of viability and proliferation. Exosome-mediated cancer cell behavior was extensively studied by performing immunofluorescence staining and gene expression studies. The effects of exosomes of immune system member macrophages on in vitro wound healing potential (scratch assay) and anti-cancer drug resistance were investigated. According to the findings, it was observed that M0 macrophage exosomes have duality in immune response while M1 macrophage exosomes suppress the metastasis of glioblastoma cells, and M2 macrophage exosomes contribute to the progression of glioblastoma cells. Consequently, it is thought that macrophage exosomes will offer new strategies for therapeutic targets through their immunomodulatory properties.