Fig. 2. Transactivation of L1 promoter activity by Rb is ablated by HPV E7 viral oncoprotein.
Transient transcription assays in HeLa cells with 500 ng of either the pBASIC-luciferase or the pL1Md-A5-luciferase reporter vectors and the forced overexpression of HPV E7 or pRb alone or in combination are shown. As an internal control for normalization, 10 ng of a second reporter vector, Renilla luciferase (pRL), were cotransfected within each experiment. (A) pBASIC-luciferase reporter activity corrected for pRL after cotransfection with 100 ng of empty vector control, HPV E7, Rb or HPV E7 and Rb together. (B) pL1Md-A5-luciferase reporter activity corrected for pRL after cotransfection with 100 ng of empty vector control, HPV E7, Rb or HPV E7 and Rb together. Cells were transfected for 6 hours, allowed to recover for 30 hours prior to luciferase activity measurements. Results are expressed as arbitrary luciferase units (ALU) and represent the mean ± S.D. of triplicate experiments after normalization to pRL. Statistic analyses were done using ANOVA (*, **, and *** indicate statistically significant differences, p<0.05, p<0.005 and p<0.0005 respectively). Each experiment was repeated at least 2 times.