Transient transcription assays in HeLa cells with the pBASIC-luciferase (A), or the pL1Md-A5-luciferase (B), reporter vectors showing the effects of 0.06% DMSO or 3 μM BaP with or without HPV E7 oncoprotein forced overexpression. Cells were transfected for 6 hours, allowed to recover for 18 hours and chemically treated for 16 hours. 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.