Fig. 5

Mortalin treatment, overexpression and knockdown modulates PARP1 signaling. Western blots showing increase in p300, PARP1 and decrease in p53 levels in mortalin-overexpressing MCF7 cells; quantitation is shown on the right (a). Mortalin-compromised cells showed decrease in p300, PARP1 and Pro-caspase 3; p53 and cleaved caspase showed increase in the same cells; quantitation is shown on the right (b). Immunostaining also showed increase in PARP1 in mortalin-overexpressing cells and decrease in mortalin-knockdown cells (Scale bar = 20 μM) (c). PARP1-DNA trapping assay revealed trapping of PARP1 in DNA in mortalin-compromised cells. Upper panel shows the input. The lower panel showed trapping assay; histone H3 was used as a loading control (d). Mortalin-overexpressing and knockdown cells showed resistance and sensitization to Mortaparib, repectively, as determined by Crystal violet staining (e) and cell viability assay (f). The quantitative data represents mean ± SD obtained from 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