FIG 8.

HPV-16 E7 enhances protein expression from cellular IRES containing mRNAs. (A) 16E7 enhances the protein expression from three IRES-containing mRNAs. Results show the Western blot analysis of transduced NIKS plated and harvested as described for Fig. 1A. Results from a representative experiment in a cohort of three independent experiments are shown. (B) IRES containing mRNAs have significantly enhanced protein levels in 16E7 NIKS cells. Values were normalized to vector-transduced cells. Results shown represent the quantitation of three independent experiments (*, P < 0.05). (C) A single point mutation in E7 reverses the enhanced expression of IRES-containing proteins. Results show the Western blot analysis of retrovirally transduced NIKS that were plated and harvested as described for Fig. 1A. Results show a representative experiment at 30 min from a set of three independent experiments. (D) Relative RNA levels of IRES-containing proteins remain unchanged in 16E7 NIKS. Transduced NIKS were plated as described for Fig. 1A, and RNA was harvested according to a TRIzol protocol. Values were normalized to vector-transduced cells. Statistics were calculated from three independent experiments each performed in duplicate and showed no significant differences between samples. (E) HPV-16 E7_H73E reverses the enhancement of the c-MYC protein observed in HPV-16-transfected keratinocytes. NIKS containing the complete HPV-16 genome or the HPV-16 E7_H73E genome were processed as described for Fig. 1A. Shown is a representative figure from two independent experiments.