Figure 2. Treatment with C16 and C51 affects steady-state levels of CUGBP1 protein. (A and B) western blot analyses of CUGBP1 protein in lysates from two different human DM1 myoblasts (Line 1 and 2) grown either with or without C16 and C51 at the indicated concentrations. Treatment with C16 and C51 led to a dose-dependent downregulation of CUGBP1 steady-state levels in DM1 cells. Equal protein loading was determined by immunoblotting for two reference controls, GAPDH and α-Tubulin, to assure that the drugs affected CUGBP1 rather than any reference protein. The bar graph shows the levels of CUGBP1 as determined in independent experiments relative to α-Tubulin. The data are expressed as the mean (± SEM) of triplicate experiments. For more data on the CUGBP1 levels, please refer to Figure S1. (C) Semiquantitative RT-PCR analyses of CUGBP1 mRNA levels in human DM1 myoblasts grown either with or without C16 and C51 at the indicated concentrations. These treatments had no effect on CUGBP1 transcript levels. *, P < 0.01; **, P < 0.001 for treated vs. untreated samples.