Fig. 3

MiR-21-5p was delivered into NSCLC cells in vitro by H-EV. a, RT-qPCR detecting miR-21-5p expression level in EV isolated from MSCs after various of treatment. i-miR or i-NC, MSCs were transfected with miR-21-5p inhibitor or microRNA inhibitor negative control before hypoxia challenge and EV isolation. Vehicle, MSCs were treated with transfection reagent without the vector. MSCs cultured in normoxic condition (Norm.) were used as negative control. b, c, RT-qPCR detecting miR-21-5p expression level in A549 and H23 cells after different treatment. d, e, RT-qPCR detecting pre-miR-21 expression level in A549 and H23 cells after different treatment. H/i-miR-EV, A549 or H23 cells were treated with EV secreted by miR-21-5p-inhibited, hypoxia pre-challenged MSCs; H-EV + miR, A549 or H23 cells were transfected with miR-21-5p inhibitor before H-EV treatment. Untreated A549 or H23 cells were used as negative control (NC). Tukey’s test was used for statistical analysis. *, p < 0.05; **, p < 0.01; ***, p < 0.001