fig4

Figure 4. CircRNA-SORE, one of the well-studied circRNAs, is transmitted via exosomes. Dotted squares indicate nuclei. Green shapes represent YBX1, while the light green shape denotes PRP19. Solid squares indicate exons. In sorafenib-sensitive HCC cells (left), YBX1 translocates from the cytoplasm to the nucleus, where it is ubiquitinated and degraded. CircRNA-SORE is generated from Exons 6 and 7 of TLE4 and is secreted via exosomes. In sorafenib-resistant HCC cells (right), transmitted circRNA-SORE binds to free YBX1 in the cytoplasm. This complex then activates various signaling pathways and confers sorafenib resistance. HCC: Hepatocellular carcinoma.