The role of HPV-18 E6 and E7 in a human basal cell carcinoma cell line

Basal cell carcinoma (BCC) is the most common skin cancer, but the pathogenic role of human papillomavirus (HPVs) in BCC is not still completely understood. In this study, we investigate the involvement of the integrated HPV-18 E6 and E7 in proliferation and senescence in a human BCC cell line. We had demonstrated HPV-18 E6 and E7 proteins in the BCC cell line. The inducible shRNA system was applied to suppress E6 and E7 expression and the cells were selected for further investigation. The effect of E6/E7 inhibition were analyzed by MTT, clonogenic assay and senescence-associated β-galactosidase staining. Our data show that repression of E6 and E7 in BCC cells result in proliferation inhibition and cellular senescence. Combined with the results of previous inducible shRNA inhibition system, we showed that HPV E6 downregulates p53 and E7 downregulates Rb proteins. Furthermore, integrated E6/E7 genes of HPV-18 upregulate the pro-inflammatory cytokines IL-6 and IL-8. These results suggest that HPV-18 involved in the tumorigenesis of BCC cell line.