Fig. 3. Reduction of p53 levels in SiHa cells transfected with p53 siRNA or nonspecific siRNA. (A) Schematic illustration of the U6 promoter-driven shRNA constructs containing the sequence targeting p53 and the scrambled sequence. (B) Upper panel: Expression levels of p53, GPX1, SESN2, SOD2 and SOD1 in control or in si-p53-expressing cells, as detected by western blot analysis. GAPDH was used as a loading control. Middle panel: Expression of SESN1 (T2) and ACTB as detected by RT-PCR. Lower panel: Quantification of p53 in western blots above normalized to GAPDH expression.