Figure 1.

siRNA-mediated downregulation of p53. PC-3 cells were treated with siRNA duplexes or non-silencing scrambled siRNA. Mock-transfected cells were treated in the same manner except that no siRNA was added. (A) Relative amounts of p53 mRNA 48 h subsequent to cell transfection with 2 µg siRNA were assessed by reverse transcription-quantitative polymerase chain reaction. **P<0.01 vs. non-silencing scrambled siRNA (Student's t-test). (B) Western blot analysis of changes in p53 protein expression level in lysates of PC-3 cells treated with 1 µg, 2 µg and 4 µg siRNA for 48 h or 72 h. Western blot analysis was performed with p53 and GAPDH antibodies. siRNA, small interfering RNA; sip53, siRNA duplexes; sc, non-silencing scrambled siRNA; mRNA, messenger RNA; GAPDH, glyceraldehyde-3-phosphate dehydrogenase; N.S., no significance.