Fig. 9

CTF2 enhanced the PMA-mediatedMMP-9 gene expression. a The nuclear translocation of CTFs/N-Cad was blocked by pretreatment with γI before exposure to PMA. NPC cells were pretreated with γI for 2 h, then co-incubated with PMA for 16 h. Total cell lysates and sub-cellular fractions underwent western blot analysis, and levels of CTFs/N-Cad were detected. GAPDH was a loading control for the cytosol fraction. Lamin B1 was a loading control for the nuclear fraction. b The reporter activity of PMA-mediatedMMP-9 was inhibited after blockade of N-cadherin intracellular cleavage. NPC cells were transfected with pGL-MMP9-Luc for 24 h, then pre-treated with γI for 2 h and co-incubated with PMA for 16 h. β-galactosidase activity in each transfection was used to normalize luciferase activity. The luciferase activity is presented relative to the control group (PMA-untreated cells). Data are mean±SEM. N = 3, ^*p<0.05. c Exogenous expression of CTF2/N-cad enhanced PMA-upregulatedMMP-9 expression. NPC cells were transfected with pEGFP-C1 (C1) or pEGFP-CTF2 (CTF2), then treated with PMA for 16 h. Cell lysates underwent western blot analysis with the indicated antibodies. Exogenous CTF2-conjugated EGFP is shown as a band of ~60 kDa. Data are mean±SEM. N = 3, ^*P<0.05. d Exogenous expression of CTF2 enhanced the reporter activity of MMP-9. NPC cells were transfected with p-EGFP-CTF2 or pEGFP-C1 in the presence of pGL-MMP9-Luc for 24 h, then exposed to PMA for 6 h. Luciferase activity is relative to the pEGFP-C1- transfected group. Data are mean±SEM. N = 3, ^*P<0.05