Figure 1. RNAi-mediated knock-down of HPV E6 and HPV E7 in SiHa and CaSki cells, and effects on p53 and retinoblastoma protein.. (A) mRNA qRT-PCR determinations 48h post-transfection as indicated, mean ± s.d. of three determinations. Asterix indicates differential effect of E7 siRNA on E6 mRNA levels in SiHa versus CaSki cells. (B) Relative positions of siRNA sequences along the bicistronic E6/E7 transcript. (C) Relative levels of E6 and E7 mRNAs 48h post-transfection of SiHa cells with the indicated siRNAs. (D, E) Immunoblots showing effects of E6 or E7 depletion on levels of p53, p21 and hyperphosphorylated Rb (pRb*) in SiHa cells.