Fig. 6

EVs transfer miR-181a and confer PARPi resistance. A Western blotting analysis of the tetraspanins CD9, CD63, and CD81 in whole cell extracts (WC) and extracellular vesicles (EVs) collected from HCC1937 and HCC1395 parental cell lines. B–C Characterization of HCC1937 parental cell line derived EV (parental-EV) and HCC1937 OlaR cell line derived EV (OlaR-EV) by NTA and FL-NTA (B) or ACE (C). The yellow arrowhead indicates the EVs that were bound to the Chip and stained by labeled anti-CD9 antibody. D Quantification of miR-181a levels by RT-qPCR comparing isolated EVs from parental (parental-EV) and OlaR (OlaR-EVs) cell lines (Student’s t-test). E–F Quantification of miR-181a (E) and STING mRNA (F) levels by RT-qPCR comparing HCC1937 parental cell line untreated or incubated with parental-EVs or OlaR-EVs (One-way ANOVA). G. Western blotting analysis for STING and β-actin (loading control) comparing HCC1937 parental cell line untreated or incubated with parental-EVs or OlaR-EVs. H Drug sensitivity assays comparing HCC1937 parental and OlaR cell lines incubated with parental-EVs or OlaR-EVs and treated with different concentrations of olaparib (One-way ANOVA and Sidak’s multiple comparisons test). *p < 0.05, **p < 0.01, ***p < 0.001. Cell viability assays were performed in triplicates