Figure 4.

Glioblastoma cells secrete CD9 and CD81-positive EVs. (A, B) A172, LN229, T98G and U373 glioblastoma cells were permeabilized and stained with fluorophore-coupled antibody against CD9 or CD81 before analyzing by flow cytometry. As control, idiotype-matched antibodies (IgG) were used. Representative histograms showing fluorescence intensity (FI) are presented in (A), while specific FI was calculated in (B). N=3, **p < 0.01; ***p < 0.001. (C) 24 h after plating glioblastoma cells, medium was replaced by 2 mL of EV-free culture medium. Supernatant was collected after 72 h EVs in supernatant were quantified using IFCM analyses. Objects numbers in supernatants used as non-irradiated controls in irradiation experiments with photons (blue bars) and protons (red bars) were compared. N = 6. *p < 0.05; **p < 0.01; ***p < 0.001.