Fig. 5

Exosomes derived from cetuximab-resistant cells conferred drug resistance to sensitive cells and altered UCA1 expression. Caco2-CS cells were treated with cetuximab for 48 h before flow cytometry analysis after coculture with or without CR-exo for 24 h. The apoptotic rates of Caco2-CS cells exposed to cetuximab were analyzed in four samples: Caco2-CS cells (CS), Caco2-CS cells coincubated with 1 μg CR-exo (CS + 1 μg CR-exo), Caco2-CS cells coincubated with 5 μg CR-exo (CS + 5 μg CR-exo), and Caco2-CS cells coincubated with 10 μg CR-exo (CS + 10 μg CR-exo). a The results are representative of three independent experiments (the mean apoptotic rate ± SD). Apoptotic rates in the CS + 10 μg CR-exo and CS + 5 μg CR-exo groups were significantly increased compared with those in the CS and CS + 1 μg CR-exo groups (*p < 0.05), while the difference between the CS + 5 μg CR-exo and CS + 10 μg CR-exo groups was not significant. b The UCA1 expression level significantly increased in a dose-dependent manner in the above four groups of CR-exo-treated cells: groups incubated with greater amounts of CR-exo showed higher UCA1 expression. Different symbols indicated the significant differences (p < 0.05) (*compared with CS; **compared with CS + 1 μg CR-exo; ***compared with CS + 5 μg CR-exo)