Figure 2.

Inducible HPV16E6E7 knockdown inhibits the in vivo tumorigenicity of HPV16+ SCC. (A) Chemoprevention model. UMSCC47-shRNA4 (1 × 10⁶) cells were implanted subcutaneously into the flanks of 7- to 8-week-old, female athymic nude mice and fed control diet or doxycycline-containing diet (200 mg/kg doxycycline hyclate) ad libitum. **** p < 0.0001. (B) Therapeutic model. UMSCC47-shRNA4 (1 × 10⁶) cells were implanted subcutaneously into the flanks of 7- to 8-week-old, female athymic nude mice and fed a control diet until the development of established tumors. Subsequently, animals were randomized to continue to receive the control diet or doxycycline-containing diet (200 mg/kg doxycycline hyclate) ad libitum. *** p < 0.001.