Fig. 5.

DHFR knockdown impacts MAPKs activity. The expression and phosphorylation levels of mitogen-activated protein kinases (MAPKs), including ERK1/2, SAPK/JNK and p38, were tested by western blot with specific antibodies (dilution 1:1,000) after DHFR knockdown for 72 h. β-actin served as internal loading control (dilution 1:8,000). (A) Representative gels from 3 experiments are shown. “p-” means phosphorylated state. (B) Densitometric analysis was performed for each protein band relative to β-actin in the same sample using Image Lab^TM software. To compare the relative quantity (RQ) of proteins between NC-siRNA and DHFR-siRNA groups, the values of density ratio in NC-siRNA group were normalized to 1.00. *vs NC-siRNA, p<0.05; **vs NC-siRNA, p<0.01.