SiRNA2-CDC25B reduces CDC25B expression in Hep3B and Hep40 cells. A) Both CDC25B mRNA and expression levels were reduced dose-dependently by siRNA2-CDC25B in Hep3B cells. B) Both CDC25B mRNA and expression levels were reduced dose-dependently by siRNA2-CDC25B in HepG2 cells. Cells were transfected with siRNA2-CDC25B at different concentrations (1, 12.5, 25, 50 and 100 nM) for 48 hours and RNA extracted for analysis by quantitative real-time PCR as described under 'Materials and Methods'. Cell were harvested and lysed and Western blotting was performed as described. The level of CDC25B mRNA expression was normalized with that of human 18s RNA expression. The level of CDC25B mRNA in the untransfected cells were designated as 100%. Columns, mean of three independent experiments; bars, SD. Cells were harvested 48 hours after transfection and cell lysates detected for CDC25B and β-Actin using Western blot.