Fig. 8

CircPAK1 transmits lenvatinib resistance by exosomes. A The level of circPAK1 in the two lenvatinib-resistant HCC cell lines was assessed by qRT-PCR. B The knockdown efficiency of circPAK1 in the two lenvatinib-resistant HCC cell lines was assessed by qRT-PCR. C The effect of circPAK1 knockdown on lenvatinib resistance was assessed by CCK8 assay. D TEM and NTA of exosomes isolated from LM3-LR and Hep-3B-LR culture media, scale bar, 100 nm. E Exosomal protein positive markers (Alix, Tsg101 and CD9) and negative marker (Calnexin) detection by western blot from purified exosomes and exosome-depleted cell extracts. F qRT-PCR analysis showed that exosomal circPAK1 was upregulated in lenvatinib-resistant cells in contrast to parental cells. G Intercellular trafficking of exosomes among different cell lines by isolated exosomes labeled with PKH67 dye, scale bar, 100 nm. H Treatment with exosomes derived from LM3-LR and Hep-3B-LR cells increased circPAK1level, however this effect was abrogated when LM3-LR and Hep-3B-LR cells were silenced with circPAK1. I cell viability in exosome-treated parental cells