Fig. 4

Analysis of synergistic effect of olaparib with doxorubicin. Cell metabolic activity after incubation with olaparib (96 h), doxorubicin (48 h), or preincubation with olaparib for 48 h and following exposure to the combination of doxorubicin and olaparib for the next 48 h (MTT assay) (A). Combination indexes (CI) of olaparib and doxorubicin in GL-1 and CLBL-1 cells (B). ± indicates nearly additive, + slight synergism, ++ moderate synergism, +++ synergism. The asterisks (*) are used to represent comparative statistically significant results. *P <.05; **P <.01; ****P <.0001; ns– not significant (P >.05)