Fig. 6: C-X-C chemokine receptor type 4 (CXCR4) was the downstream target of miR-186-5p and miR-548c-3p.

A, B The predicted binding sites between miR-186-5p/miR-548c-3p and CXCR4 mRNA. C, D The luciferase reporter assay was performed in MDA-MB-231 and BT-549 cells that were co-transfected with CXCR4 WT/MUT luciferase vector and miR-186-5p mimic/miR-548c-3p mimic/mimic NC. E–L MDA-MB-231 and BT-549 cells were transfected with miR-186-5p/miR-548c-3p mimic or miR-186-5p/miR-548c-3p inhibitor or corresponding negative controls (mimic NC or inhibitor NC). The expression levels of miR-186-5p/miR-548c-3p were measured by RT-PCR. The protein level of CXCR4 was measured by western blot. GAPDH was used as an internal control. M The protein level of CXCR4 was measured in TNBC cancerous tissues (n = 38) and ANT (n = 38). ***P < 0.001. N The correlation plot of circBACH2 level and CXCR4 protein level in TNBC cancerous tissues (n = 38). O MDA-MB-231 and BT-549 cells were divided into six groups: sh-NC + inhibitor NC (in-NC), in-NC + sh-circBACH2, sh-NC + in-miR-186-5p, sh-circBACH2 + in-miR-186-5p, sh-NC + in-miR-548c-3p, and sh-circBACH2 + in-miR-548c-3p. The protein level of CXCR4 was measured by western blot. GAPDH was used as an internal control. **P < 0.01, ***P < 0.001 vs mimic NC; ^##P < 0.01, ^###P < 0.001 vs inhibitor NC.