Roles of Bile-Derived Exosomes in Hepatobiliary Disease

Figure 4

The mechanism of action of biliary exosomes in cholangiocarcinoma. circ-CCAC1, which is highly expressed in bile exosomes of patients with cholangiocarcinoma, can enhance the transcription of CAMLG in cholangiocarcinoma cells by sponging miR-514a-5p and upregulating YY1; CAMLG promotes the progression of tumour cells. circ-CCAC1 can be loaded into the exosomes and uptaken by vascular endothelial cells. This circRNA enters the cytoplasm and binds to EZH2 to reduce its intranuclear transport, decrease the formation of H3K27me3, and promote the transcription of SH3GL2; then, SH3GL2 level is increased to negatively regulate ZO-1/occludin and eventually destroy endothelial barrier function, promoting tumour angiogenesis.