Fig. 5. Gene silencing of CD147 induces upregulation of NOD2-mediated NF-B activation and IL8 release. HEK^NOD2 cells and SW480 cells expressing endogenous NOD2 were transfected with pSUPER.neo+GFP vectors containing three different target sequences for CD147 (CD147-si1 to si3) or irrelevant control sequence (ctrl-si). (A) After selection and sorting, HEK^NOD2 cells were assayed for CD147 expression by immunoblotting. Equal loading was monitored by concomitant detection of β-actin (lower panel). (B) Stably transfected shRNA HEK^NOD2 cells were stimulated with MDP or left untreated. Induction of NF-B activity was determined as described in Materials and Methods. Data are expressed as relative luciferase activity (RLU, mean ± s.d.; n=3 independent experiments). (C) Transiently transfected SW480 cells were stimulated with MDP (50 µg/ml) overnight and assayed by ELISA for IL8 release. Gene silencing of CD147 augmented NF-B activation and IL8 secretion in both transfected HEK293 cells and SW480 cells expressing endogenous NOD2 (⁺⁺P<0.01 for MDP-stimulated versus unstimulated cells; ^**P<0.01 for CD147-si versus ctrl-si).