Figure 7. Cytotoxicity screen to identify chemicals bioactivated and detoxified by CYP metabolism.
HEK293T cells were transfected with 25 ng of βgalactosidase or 24 ng of CYP1A2, CYP2A6, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, CYP2E1, CYP2J2, CYP3A4, or a 10-CYP liver mix (Table 1 for ratio) + 1 ng P450 oxidoreductase mRNA at a lipid:mRNA ratio of 2.5 and delivered at 5 μL per well. Fifty-six test compounds (Table S5) were delivered at a volume of 225 nL with an acoustic dispenser (0.5% DMSO final) using randomized plate designs at final concentrations ranging from 1–100 μM (x-axis) at 6 hours post-transfection and incubated for 36 hours. Cytotoxicity (y-axis) was measured in three replicate experiments and normalized data fit with a 3-parameter Hill model (bottom constrained to zero, dashed black line). Red dashed line showed the mean ± 2*sd for the DMSO vehicle control wells. Shown are example curves for aflatoxin B1 (A), amodiaquin (B), amitripytyline (C), 8-quinolinol (D), azobenzene (E), and fenazaquin (F). All ten CYP singlets and liver mix were run for each chemical; however, for clarity only βgal, liver mix and those CYP singlets showing bioactivation or detoxification were plotted. See Supplemental Figure 1 for all curves and bio-groups.


