Fig. 4: Effects of miR-21 on EGF signaling and effects of signaling inhibitors on EGF-induced cell growth.

a, b After being serum-starved for 24 h, PANC-1 and MIA PaCa-2 cells were transfected with miR-21 mimics and inhibitor or negative control and simultaneously treated with or without EGF (50 ng/ml) for the indicated times. Western blotting analysis of the indicated proteins was then carried out. Western blotting expression densitometry data was quantified by imageJ and then was normalized to the corresponding densitometry of GAPDH. c After being serum-starved for 24 h, PANC-1 cells transfected with miR-21 mimics were incubated for 36 h without EGF (SF) or with EGF(50 ng/ml) in the absence (DMSO) or presence of erlotinib (1 µM), MK-2206 (1 µM) or UO126 (1 µM) and the cell numbers were counted. Three independent experiments were performed for each group. All data are represented as the mean ± SD. *P < 0.05 compared with DMSO group. ns, not significant between the ER and MK + UO groups