Fig. 1

CRISPR/Cas editing of the HPV E6 and E7 genes reduces cell viability and induces key growth control proteins. A HeLa (HPV18 positive) cells were treated with target-specific gRNAs or control for 48 h before protein expression of various growth control proteins (p53 for E6 targeting, RB for E7 targeting) was determined by western blot analysis. B The relative density of bands was quantified using ImageJ software. C qRT–PCR Measurement of expression of sgRNA. *p < 0.05, **p < 0.01 vs. control. D E6 and E7 mRNA expression in the HeLa cells was decreased significantly after transfection for 48 h. *p < 0.05, **p < 0.01 vs. control. E Examples of direct sequencing of PCR products containing targeted sites. F and G CCK-8 assay and cell apoptosis assay. Cells were treated with target-specific gRNAs (E6, E7, or E6E7), transfected for 48 h before CCK-8 assay and cell apoptosis assay. *p < 0.05, **p < 0.01 vs. control