Fig. 4. Assessment of c-Myc mRNA and ERK phosphorylation in neural stem cells. (A) c-Myc mRNA expression was reduced in the let-7a mimic treatment with agmatine group in comparison with let-7a mimic group. β-actin was used as an internal control. (B) ERK phosphorylation significantly increased in the let-7a mimic treatment with agmatine group compared to let-7a mimic group. GAPDH was used as an internal control. Data are expressed as mean±SEM. ^*p<0.05, ^†p<0.001 compared to normal control group, ^‡p<0.05 compared to let-7a mimic group. let-7a mimic, let-7a mimic treatment/let-7a overexpression group; let-7a inhibitor, let-7a inhibitor treatment/let-7a suppression group; Agm, 100 µM agmatine treatment group; Veh, Lipofectamine treatment group; p-ERK, ERK phosphorylation.