Figure 6.
IFNγ enhances cytotoxicity in human BRCA1 tumor cells exposed to a PARP inhibitor in vitro. BRCA1 UWB1.289 cells or UWB1.289 cells transfected with competent BRCA1 were cultured with titrated doses of the PARP inhibitor in the presence of recombinant human IFNγ or TNFα as indicated. After 72 hours, cells were analyzed for viability by flow cytometry. A, BRCA1 UWB1.289 cells exposed to IFNγ and PARP inhibition (top, PARPi dose effect, P < 0.0001; IFNγ dose effect, P < 0.0001; interaction, P 1/4 0.3872 based on two-way ANOVA; bottom, * , P < 0.05; **, P < 0.025 by Tukey multiple comparisons test). B, BRCA1 UWB1.289 cells exposed to TNFα and PARP inhibition (top, TNFα dose effect, P 1/4 0.0499; interaction, P 1/4 0.9655 by two-way ANOVA; bottom, *, P < 0.05, Tukey multiple comparisons test). C and D, BRCA1- transfected UWB1.289 cells exposed to IFNγ or TNFα and PARP inhibition (no statistically significant dose effect for IFNγ or TNFα).