Figure 4. Drosha negatively affects the stability of endogenous Lin28 mRNA targets. (A and D) PA-1 cells were transfected with siCon, siDrosha, empty vector or FL-DGCR8. Act D was added to a final concentration of 5 ug/ml 48 h post-transfection. RNAs were harvested at 0, 1, 2 and 4 h time points and levels determined by RT-qPCR analysis. Results are presented after normalization against internal control GAPDH mRNA levels with 0 time point mRNA levels arbitrarily set as 1. Numbers are mean ± SD (n = 3). (B and C) PA-1 cells were transfected with FL-DGCR8 or empty vector. Protein and RNA were isolated 48 h post-transfection and analyzed by western blot (B) and RT-qPCR (C), respectively. Results are representatives of two independent transfection experiments.