Exosome-delivered circular RNA DLGAP4 induces chemoresistance via miR-143-HK2 axis in neuroblastoma.

Accumulating evidence validates that aerobic glycolysis is involved in chemotherapy resistance in human malignant tumors. In the present study, we explored the role of exosome-delivered circular RNA DLGAP4 (circDLGAP4), a novel identified circRNAs, in the chemoresistance of neuroblastoma (NB) cells. Our study demonstrated that doxorubicin-resistant cells expressed higher HK2, accompanied with enhanced glycolysis. In addition, circDLGAP4 was validated to act as a sponge for the HK2-targeting miR-143. As a molecular cargo, exosomes were found to deliver circDLGAP4 from doxorubicin-resistant cells to the sensitive cells. Functionally, exosomal circDLGAP4 enhanced glycolysis and drug resistance via regulating miR-143 and HK2 in NB cells. Consistently, upregulation of HK2 induced by circDLGAP4 or miR-143 inhibitors produced the similar malignant transformation in NB cells. However, knockdown of circDLGA P4 could reversed the drug resistance in the recipient cells. In conclusion, these findings demonstrate that exosome-delivered circDLGAP4 promotes the glycolysis, proliferation, and invasion of sensitive NB cells by regulating miR-143 and HK2, providing a novel link between drug resistance and circDLGAP4/miR-143/HK2 axis in drug-resistant NB.