Fig. 5

Exosomes originating from CAFs activate NF-κB p65 in CRC cells, leading to the secretion of interleukin-6. A Western blot analysis of NF-κB p65 protein levels in the total cell lysate of SW480 CRC cells, 48 h after incubation with 100 μg/ml exosomes derived from CAFs or NFs. Importantly, transfection of miR-20a-5p inhibitor reduced the promoting effect of CAF-derived exosomes on NF-κB p65 protein levels in SW480 CRC cells. β-actin was used as an endogenous loading control. B Elevated nuclear (Nuc) p65 protein levels indicated NF-κB activation after treatment with 100 µg/ml exosomes derived from CAFs. Cyt: cytoplasmic fraction. The cropped blots are presented correspondingly. Full-length blots are presented in Supplementary Fig. 5. C The level of interleukin-6 (IL-6) protein secretion was evaluated using ELISA. The results revealed a significant increase in IL-6 production in CRC cells stimulated with 100 µg/ml of exosomes derived from CAFs for 48 h, in comparison to cells treated with PBS or NF-derived exosomes. The inhibition of miR-20a significantly diminished the enhancement of IL-6 production in SW480 CRC cells caused by exosomes derived from CAFs. Columns represent means of three different experiments; bars represent SD. *P < 0.05, ***P < 0.001