Figure 7. FAK gene expression can be induced by EGF.

(A) Time-course of EGF stimulation on FAK gene transcription activation in B16F1 cells. The B16F1 cells were transfected with p-170/+43-luc construct along with Renilla expressing plasmid. After transfection, the cells were serum starved for 24 h, then pulsed with EGF (100 ng) for a designated period of time. Luciferase activity of transfected cells without EGF treatment was arbitrarily set at 1. Results shown are the means ±S.D. of six replicates. *P<0.05, **P<0.01, ***P<0.001 vs. control cells. (B) Time-dependent increase of the FAK mRNA level after EGF stimulation. The B16F1 cells were serum-starved for 24 h, and then pulsed with EGF (100 ng) for 1, 2, 4 or 6 h. After treatment, total RNA (30 µg) was separated, blotted and hybridized with labelled FAK cDNA probe, and actin probe as an internal control. Representative image of 3 independent experiment results is shown. (C-D) The B16F1 cells were transiently cotransfected with 0.5 µg p-170/+43-Luc plasmid and increasing amounts of plasmids expressing the JNK(C) or ERK (D). Luciferase activity of control cells without JNK or ERK overexpression was arbitrarily set at 1, *P<0.05, **P<0.01, ***P<0.001 vs control cells. (E) Effect of ERK or JNK inhibitor on FAK gene transcription activation in B16F10 cells. The B16F10 cells were transfected with p-170/+43-Luc plasmid, then treated with 20 µM SP600125 or U0126 for 6–8 h. *P<0.05, ***P<0.001 vs control cells. (F) Effect of ERK or JNK inhibitor on EGF-induced FAK gene transcription activation in B16F1 cells. The B16F1 cells were transfected with p-170/+43-Luc plasmid along with Renilla expressing plasmid. After serum starvation for 24 h, cells were pretreated with 20 µM SP600125 or U0126 for 0.5 h, pulsed with 100 ng EGF for an additional 3–4 h. *P<0.05, ***P<0.001 vs control cells.