The activations of ERK and JNK are feedback-regulated by miR-21 via Spry1 and Pdcd4, respectively, in arsenite- transformed HELF cells.

<p>Densities of bands were quantified by Eagle Eye II software. GAPDH levels, measured in parallel, served as controls. Arsenite-transformed HELF cells were transfected with 150 nM of anti-miR-nc or anti-miR-21 for 24 h. (A) Western blots and (B) relative protein levels (means ± SD, n = 3) of p-ERK, p-JNK, Spry1, and Pdcd4. **<i>P</i><0.01 different from NC group. Arsenite-transformed HELF cells were transfected with pIRES, pIRES-Pdcd4, or pIRES-Spry1 for 24 h. (C) Western blots and (D) relative protein levels (means ± SD, n = 3) of p-JNK, p-c-Jun, and Pdcd4. (E) qRT-PCR analysis of miR-21 expression (means ± SD, n = 3). **<i>P</i><0.01 different from control group. (F) Western blots and (G) relative protein levels (means ± SD, n = 3) of p-ERK, p-NF-κB p65, and Spry1. (H) qRT-PCR analysis of miR-21 expression (means ± SD, n = 3). **<i>P</i><0.01 different from control group.