Fig. 3

Mortaparib caused inhibition of PARP1 and activation of DNA damage stress signaling in HeLa cells. Western blot analysis showed Mortaparib treatment caused downregulation of PARP1, p300 and BRCA1 and increase in cleaved PARP1 (a). Immunostaining revealed increase in cleaved PARP1 (Scale bar = 20 μM) (b) and decrease in PAR by Western blot (c) and immunostaining in Mortaparib-treated cells (d). Western blot analysis of PARP1-DNA complexes showed trapping of PARP1 in DNA in Mortaparib (2 μM) treated cells (e). Neutral comet assay showing Mortaparib induced increase in DNA damage (Scale bar = 10 μM) (f). Immunostaining of γH2AX in control and Mortaparib-treated cells showing increase in the number of γH2AX foci in the latter (Scale bar = 20 μM) (g). Western blot showed Mortaparib treatment led to increase in γH2AX (h). The quantitative data represents mean ± SD obtained from, at least, three independent experiments; p-values were calculated using Student’s t-test. * < 0.05, ** < 0.01 and *** < 0.001 represent significant, very significant and very very significant, respectively