Skip to main content
. 2021 Jun 28;22(13):6923. doi: 10.3390/ijms22136923

Figure 7.

Figure 7

The synergistic effect of PARP inhibitor and DNA alkylating agent methyl methanesul-fonate (MMS) or TMZ in vitro. Cells were treated with two-dimensional dose responses of PARP inhib-itors and DNA alkylating agents for 5 days. Excess over Bliss additivity was determined for each condition. To facilitate comparison of PARP inhibitors, cross-sections of response surfaces at the concentrations of alkylating agent eliciting peak synergism are overlaid. In this analysis, values of zero indicate no activity or additivity whereas higher values indicate stronger synergism. The decreases observed at higher PARP inhibitor concentrations are due to a loss of synergism to single-agent PARP inhibitor activity. (a) HeyA8 cells with 20 μmol/L MMS. (b) HeyA8 cells with 300 μmol/L TMZ. (c) DLD1 cells with 100 μmol/L MMS. (d) DLD1 cells with 300 μmol/L TMZ. (e) DLD1-BRCA2-/- cells with 20 μmol/L MMS. (f) DLD1-BRCA2-/- cells with 60 μmol/L TMZ. Data represent means with standard errors from at least two independent experiments run in dupli-cate. Adapted from [125].