The level of miR-21 is up-regulated, and the protein levels of Pdcd4 and Spry1 are decreased in arsenite-transformed HELF cells.

<p>Abbreviations: HELF-C, normal HELF cells; HELF-30C, passage-control HELF cells; HELF-30T, arsenite-transformed HELF cells. Densities of bands were quantified by Eagle Eye II software. GAPDH levels, measured in parallel, served as controls. HELF cells were exposed to 0.0 or 1.0 µM arsenite for 30 passages. (A) The levels of miR-21 were determined by qRT-PCR assays (means ± SD, n = 3). **<i>P</i><0.01 different from HELF-30C cells. (B) The protein levels (upper) and mRNA levels (lower) of Pdcd4 and Spry1 (target proteins of miR-21) were analyzed by Western blots and RT-PCR, respectively. (C) The relative protein levels of Pdcd4 and Spry1 (means ± SD, n = 3). **<i>P</i><0.01 different from HELF-30C cells.