Fig. 1
PARP1 and PARP2 are redundant in the cellular response to MMS-induced DNA damage. a Whole cell extracts were prepared from U2OS or two independent parp1Δ cell lines and western blotting performed with the indicated antibodies (left panel). U2OS or parp1Δ cell lines were exposed to MMS and cell survival assessed by clonogenic assays (right panel). Error bars represent the standard error of the mean (SEM) from three independent experiments. Statistical significance was determined by two-way ANOVA (*** p < 0.001). b U2OS or parp1Δ cell lines, with or without exposure to Olaparib (PARPi), were exposed to MMS and cell survival assessed by clonogenic assays. Error bars represent the SEM from three independent experiments. Statistical significance was determined as in a. c Whole cell extracts were prepared from U2OS, parp1Δ, parp2Δ and parp1/2Δ cells and Western blotting performed using the indicated antibodies. d The indicated cell lines were left untreated (-) or exposed to 1.5 mM MMS ( + ) for 1 h and nuclear ADP-ribosylation analysed by immunofluorescence. Error bars represent the SEM from three independent experiments. Statistical significance was determined using a two-tailed Student’s t-test (** p < 0.01; *** p < 0.001). e U2OS, parp1Δ, parp2Δ or parp1/2Δ cell lines were exposed to MMS and cell survival assessed by clonogenic assays. Error bars represent the SEM from three independent experiments. Statistical significance was determined as in a. f Cells were treated with 250 µM MMS for 1 h, before recovery in fresh media. Samples were taken at the indicated times post treatment and the alkaline comet assay used to reveal strand breaks and alkali-labile sites. Comet data was normalised to the untreated sample. Error bars represent mean values ± SD from at least six independent experiments. Statistical significance was determined as in d
