The biogenesis of tRF5-AlaCGC is controlled by angiogenin and Dicer. (A) A549 cells were transfected with 100 nM of siRNA against indicated proteins or scrambled siRNA as a negative control. At 40 h post transfection, the cells were treated with arsenite for 6 or 15 h. Cells without the treatment were used as controls. Total RNAs were then subjected to Northern hybridization as described in Fig. 2. 5 S rRNA and EtBr staining were shown for equal loading. (B) The suppression of target proteins by each siRNA was confirmed by Real-time PCR. (C) The target specific suppression by siRNAs was also confirmed by Western blot after 40 h post transfection. (D) Densitometric analysis of the tRF bands from three Northern blots was performed for 4A, similarly as described in Fig. 2C. Data shown are representative of three independent experiments. * and ** represent P < 0.05 and P < 0.01 respectively, relative to CN oligo-treated cells at corresponding time point of arsenite treatment.