Fig. 2

The effect of rucaparib and olaparib on PARP-1 activity. Cells were treated with 20 mM hydrogen peroxide (H₂O₂) in order to stimulate PARP-1 activity in the presence or absence of the PARP-1 inhibitors rucaparib and olaparib. Poly(ADP-ribose) (PAR) chain synthesis was detected using an anti-PAR monoclonal Alexa Fluor 488-conjugated antibody (green). The nucleus was visualised using the nuclear counterstain DAPI (blue). Representative images obtained from the analysis of anti-PAR staining of SK-N-BE(2c) cells are shown (a). Fluorescence intensity for Alexa Fluor 488 was quantified using ImageJ software and normalised to DAPI fluorescence intensity in SK-N-BE(2c) (b) and UVW/NAT (c) cells. Drug vehicles were PBS and DMSO for rucaparib and olaparib, respectively. Untreated cells were exposed to 0.09 % (v/v) drug vehicle diluted in culture medium. The designation ‘Drug Alone’ indicates that cells were treated with 10 μM PARP-1 inhibitor in the absence of H₂O₂. The designation’No Drug’ indicates that cells were treated with 20 mM H₂O₂ alone, in the absence of PARP-1 inhibitor. Data are means ± SEM, n = 3; *p < 0.05, ** p < 0.01 compared to H₂O₂ alone