Fig. 1.

PARP inhibitor potentiated TMZ response in MGMT+ GSCs. A, MGMT expression was detected in 13 GSC cell lines by western blot, MGMT promoter methylation status determined by sequencing was shown in the bottom, U for unmethylated, M for methylated. B-D, MGMT+ and MGMT− GSCs were treated with serial diluted TMZ with or without talazoparib at indicated concentration. Dose-response curves were plotted (B), IC₅₀ of TMZ calculated by GraphPad (C), Graph shows cell proliferation inhibition by TMZ, talazoparib, and combinational treatment. Synergistic effect for each cell line as calculated by bliss model was shown in the bottom (D). E, Effect of combination of TMZ and talazoparib on sphere formation in MGMT+ and MGMT− GSCs. Synergistic effect for each cell line as calculated by bliss model was shown in the bottom. Abbreviations: GSCs, glioma sphere-forming cells; MGMT, O⁶-methylguanine DNA methyltransferase; PARP, poly(ADP-ribose) polymerase; TMZ, temozolomide.