Fig. 6

CTHRC1 upregulates cyclin D1 and snail1/MMP14 by activating the MAPK/MEK/ERK/FRA-1 cascade. a The relative mRNA levels of FOSL1, CCND1, SNAI1 and MMP14 in CTHRC1-knockdown cells or CTHRC1-overexpressing cells and control cells were detected by RT-PCR. b Western blot was conducted to detect the protein levels of CTHRC1, p-FRA-1, FRA-1, cyclin D1, snail1 and MMP14 in CTHRC1-knockdown KYSE510 and KYSE30 cells and corresponding vector control cells. c CTHRC1-overexpressing KYSE450 cells and control cells were treated with U0126 (10 μM) or DMSO. The protein levels of CTHRC1, p-FRA-1, FRA-1, cyclin D1, snail1 and MMP14 were detected by western blot. d, e CTHRC1-overexpressing KYSE450 cells and control cells were transfected with FRA-1 siRNA or negative control (NC) siRNA. d Cell viability was measured using the CCK8 assay. e Migration and invasion of cells were investigated using transwell assays. The results are shown as the mean ± SD. The difference between groups was analysed using two-tailed Student’s t-test. *P < 0.05 and **P < 0.01. f CTHRC1-overexpressing KYSE450 cells were transfected with FRA-1 siRNA or snail1 siRNA. The protein levels of CTHRC1, FRA-1, cyclin D1, snail1 and MMP14 in KYSE450 cells with different treatment were detected. g Schematic diagram illustrating the proposed CTHRC1-mediated activation of ERK1/2 signalling pathway and its role in ESCC cells