Exosomal circ_0037104 derived from Hu-MSCs inhibits cholangiocarcinoma progression by sponging miR-620 and targeting AFAP1

Exosomes are membrane-enclosed nanovesicles that shuttle active cargoes, such as circular RNAs (circRNAs) and microRNAs (miRNAs), between different cells. Human umbilical cord-derived mesenchymal stem cells (Hu-MSCs) can migrate to tumor sites and exert complex functions throughout tumor progression. In this study, we successfully isolated Hu-MSCs from human umbilical cords based on their surface marker expression. Hu-MSC-derived exosomes significantly reduced the invasion, migration, and proliferation of cholangiocarcinoma (CCA) cells. Furthermore, circ_0037104 was downregulated in CCA and inhibited the proliferation and metastasis of CCA cells. Then, we investigated the effect of Hu-MSC-derived exosomal circ_0037104 on CCA. Circ_0037104 mainly regulates miR-620 and enhances APAF1 expression, inhibiting CCA cell proliferation and metastasis. Overall, Hu-MSC exosomal circ_0037104 contributes to the progression and stemness of CCA cells via miR-620/APAF1. In conclusion, Hu-MSC-derived exosomal circ_0037104 sponges miR-620 directly and negatively targets APAF1 to suppress CCA.