Figure 1. CircFOXK2 is upregulated in highly metastatic BC cells. (A) Migration ability of BT-549 cells with high and low potential of metastasis (BT-549-H and BT-549-L). Scale bar: 20 μm. (B) Invasion ability of BT-549 cells with high and low potential of metastasis (BT-549-H and BT-549-L). Scale bar: 20 μm. (C) Lung metastasis of mice injected with BT-549 or BT-549-H cells through the tail vein, as determined by H&E stain. Scale bar: 100 μm. (D) The expression of Ki67 in lung tissues of mice injected with BT-549 or BT-549-H cells through the tail vein, as determined by IHC assay. Scale bar: 40 μm. (E) Cell viability of BT-549-H and BT-549-L cells. (F) Volcano plot of differentially expressed circRNAs between BT-549-H and BT-549-L cells. (G) Heatmap for expressions of top 10 upregulated and downregulated circRNAs between BT-549-H and BT-549-L cells. (H) Cellular distribution of circFOXK2 in BT-549 cells, as detected by RNA FISH assay. Data were represented as mean ± SD. Each experimental group had at least three replicates. *p < 0.05, **p < 0.01, ***p < 0.001.