Fig. 6.

a Cell viability in AAI-exposed MEFs. Trp53(+/+), Trp53(+/−) and Trp53(−/−) MEFs were exposed to 10 μM (upper panel), 50 μM (middle panel) and 100 μM (lower panel) AAI for 24 and 48 h. Controls were exposed to water only. Cell viability was assessed with the crystal violet assay following 24 and 48 h exposure to AAI. Results are presented as mean ± SD (n = 3/group) derived from independent experiments with cells from different stocks from the same embryo. b Protein expression in AAI-exposed MEFs. Western blot analysis of p53, p21, Nqo1 and Cyp1a1 expression at 24 and 48 h (50 μM AAI). Gapdh expression was used as a loading control. Representative images of Western blots are shown; at least duplicate analyses from independent experiments were performed. c DNA adduct formation in AAI-exposed MEFs. AAI-DNA adduct formation (RAL, relative adduct labelling; 50 μM AAI) was determined by the nuclease P1-enrichment version of the ³²P-postlabelling method. Results are presented as mean ± SD (n = 4/group) derived from independent experiments with cells from different stocks from the same embryo. d Gene expression in AAI-exposed MEFs. The fold change (50 μM AAI) for Nqo1 (upper panel) and Cyp1a1 (lower panel) is the fold change in expression relative to the water control for each cell type. Gene expression was determined by qRT-PCR and the 2^−ΔΔCt method. Results are presented as mean ± SD (n = 4/group) derived from independent experiments with cells from different stocks from the same embryo. Statistical analysis was performed by two-way ANOVA and Bonferroni’s post hoc test (**p ≤ 0.01, ***p ≤ 0.001, comparison as indicated); and by one-way ANOVA and Tukey’s post hoc test [^#p ≤ 0.05, ^####p ≤ 0.0001, in comparison to Trp53(+/+) within that exposure group]