A. Western blotting confirmed efficiency of the MEX3C and AP-2 siRNAs. MEX3C was detected 24 hours after siRNA transfection; the loading control was β-actin. AP-2 α and AP-2 μ2 were examined 84 hours after siRNA transfection (after EV collection). The loading control was GAPDH. The panel on the right shows the relative expression after normalized to loading control determined by densitometry. Results are representative of two independent experiments. B. Real-time PCR analysis of EV RNA expression after MEX3C or AP-2 inhibition. Because inhibiting AP-2 α or AP-2 μ, or AP-2 α and AP-2 μ in HEK293T cells showed similar effects, these data were combined. * indicates p<0.001 by Tukey's multiple comparison test following ANOVA. For miR-451a and miR-320a, N = 3; for the others, N = 2. C. MEX3C or AP-2 inhibition did not affect cellular miR-451a expression (N = 3). D. EV miR-451a was protected from RNase by membrane (N = 5). ***, p<0.0001 between protease K and RNase treated samples with and without NP40 pre-treatment, analyzed by Tukey's multiple comparison test following ANOVA. For B, C and D, means ± standard error (s.e.m.) are shown.