Fig. 5.

Exploring the impact of SBI-797812 on sirtuin and PARP-1 activities. a SBI-797812 decreases histone H4 acetylation. A549 cells treated with vehicle or SBI-797812 (10 μM) for 4 h. Histone H4 and H4-AcK16 levels determined by western blotting. Normalized signal ratios are shown. *p = 0.005 vs. control; n = 4. Two-tailed unpaired t test used. b, c Impact of SBI-797812 on PARP-1 activation. A549 cells treated with vehicle or SBI-797812 (10 μM) for 4 h. Where indicated, A549 cells were also treated with H₂O₂ (0.5 mM) for 30 min before harvest. Cell lysates were prepared with (b) or without (c) olaparib and analyzed by western blotting. Cell lysates probed with PAR and PARP-1 antibodies (b). Signal intensities determined with Licor Imaging system. PAR:PARP-1 signal ratios normalized to vehicle, no H₂O₂ (assigned value = 1). Data shows means ± s.d., n = 4. *p < 0.002 vs. vehicle; #p < 0.01 vs. SBI-797812. One-way ANOVA with Tukey’s multiple comparisons test. Panel c shows western blotting of A549 cells treated with vehicle or SBI-797812 (10 μM) for 4 h; cell lysates prepared without olaparib and probed with anti-PAR antibody. For Fig. 5a–c, source data are provided as a Source Data file