Figure 4. IGF2BP3 is critical for the effect of circFOXK2 on BC metastasis. (A) Prediction of RNA-binding proteins of circFOXK2. (B) Interaction between circFOXK2 and IGF2BP1, IGF2BP2, IGF2BP3, EIF4A3, FMRP, HuR, and AGO2, as determined by RNA pulldown and Western blotting assay. (C) Protein expression of IGF2BP3 in BT-549 cells transfected with IGF2BP3-expressing plasmids or IGF2BP3-specific small interfering RNA (siRNA). (D) Pearson correlation between the expressions of circFOXK2 and IGF2BP3. (E and G) Rescue experiments for the migration ability of BT-549 cells treated as indicated. Scale bar: 20 μm. (F and H) Rescue experiments for the invasion ability of BT-549 cells treated as indicated. Scale bar: 20 μm. Data were represented as mean ± SD. Each experimental group had at least three replicates. *p < 0.05, **p < 0.01, ***p < 0.001.