Fig. 8.

PARP inhibition potentiates BPDE-induced mutagenicity. An HPRT mutagenicity assay with BPDE-treated CHO cells was performed in the absence or presence of 10-µM ABT888. a Representative cell culture dishes of the HPRT assay. A BPDE dose-dependent increase in colony numbers (mutant frequency) was observed. PARP inhibition further increased BPDE-induced mutagenicity. b, c Quantification of (a) increasing concentrations of BPDE resulted in increased numbers of mutations of the HPRT gene. b BPDE treatment with concentrations of up to 500 nM. c Magnification of insert in B showing data of the low-dose range, with BPDE concentrations of up to 50 nM. When PARP activity was inhibited, an even higher mutation rate was observed. Data represent means ± SEM of four independent experiments. Statistical evaluation was performed using two-way ANOVA analysis followed by Sidak’s multiple comparison testing. *p < 0.05, **p < 0.01