Fig. 6

The GRK6/β-Arrestin/MAPK signalling axis induces NF-κB transcription factor activity to force the EMT progression and cellular migration activity in TNBC cells. A–D. Western blot analyses (upper) for the p-NF-κB, total NF-κB and GAPDH in the whole cell lysates and luciferase reporter assays (lower) for the NF-κB DNA-binding activity in the indicated HCC1937 cell variants (A), MDA-MB231 cells treated without or with GRK6 inhibitor at the indicated concentrations (B), and the VC/GRK6A-OE HCC1937 cells treated without or with β-Arrestin inhibitor (C) and MAPK inhibitors (D) at the indicated concentrations for 24 h. E–F. Western blot analyses for the EMT markers in the whole cell lysates (E), and Giemsa stain for the migrated cells in the trans-well cultivation (F, upper) of VC and GRK6A-OE HCC1937 cells treated without or with NF-κB inhibitors BAY-11-7082 (BAY) and SN50 at the indicated concentrations for 24 h. The migration cell number from three independent experiments were presented as mean ± SEM in the histogram (F, lower). The different alphabets indicate the statistical significance at p < 0.05. In A, B, C, D and E, GAPDH was used as an internal control of protein loading