Fig. 5

CircCD44 inhibits miR-502–5p-mediated KRAS degradation. A The relative KRAS RNA level was detected in different cells with the indicated modifications; ***, P < 0.001. B Immunoblot of KRAS in cells with the indicated modifications. C Schematic image of the binding site between miR-502–5p and circCD44 and the mutant allele. The binding site was obtained from the online tool, TargetScan, and the mutant allele was established as illustrated. D HEK293T cells were transfected with different plasmids or microRNAs as indicated. Relative luciferase activity was detected and normalized to the control; ***, p < 0.001. E miR-502–5p inhibitor was transfected into circCD44 knockdown cells, and miR-502–5p mimic was transfected into circCD44-overexpressing cells (these two cell lines were named “Rescue”). Immunoblot for KRAS and downstream AKT signaling components in TNBCs with the indicated modifications was detected. Data are representative of at least 2–3 experiments with similar results