The regulation of hsacirc_004413 promotes proliferation and drug resistance of gastric cancer cells by acting as a competing endogenous RNA for miR-145-5p

BACKGROUND: Whether circRAN, which acts as a microRNA sponge, plays a role in 5-fluorouracil (5-Fu) resistant gastric cancer has not been reported. In this study, a 5-Fu resistant cell line with an IC50 of 16.59 µM was constructed. METHODS: Using comparative analysis of circRNA in the transcriptomics of resistant and sensitive strains, 31 differentially expressed circRNAs were detected, and the microRNA interacting with them was predicted. RESULTS: Hsacirc_004413 was selected for verification in drug resistant and sensitive cells. By interfering with hsacirc_004413 using antisense RNA, the sensitivity of drug resistant cells to 5-Fu was significantly promoted, and the apoptosis and necrosis of the cells were significantly increased. In sensitive cells, inhibition by inhibitors enhanced the resistance of cells to 5-Fu. We hypothesize that hsacirc_004413 makes gastric cancer cells resistant to 5-Fu mainly through adsorption of miR-145-5p.