Fig. 1

Modulation of CBP level and activity under DNA damage. a MCF7 and T47D cells were treated with 5 µM of Doxorubicin (DOX) for 4 and 8 h, followed by immunoblotting analysis for CBP, γH2AX, H2AX, acetyl-p53, and p53 proteins. b, c Graphs showing band quantifications for the indicated proteins in c MCF7 and d T47D cells, normalized to β-actin levels. d Upper panel: Immunoblot analysis for CBP expression in MCF7 and T47D cells treated with 5 µM of Cisplatin (CIS), Mitomycin C (MMC), Doxorubicin (DOX), and Etoposide (ETOP) for 8 h. Lower panel: Band quantification of CBP expression, normalized to β-actin levels and presented as fold change relative to control samples. e Left panel: Proximity ligation assay (PLA) for CBP and γH2AX colocalization (red) in T47D cells after 5 and 30 min of 2 Gy ionizing radiation (IR) or after 4 and 8 h treatment with 5 µM of ETOP or CIS. DAPI staining (blue) marks the nucleus. Scale bar, 100 µm. Right panel: Quantification of PLA signals from 100 cells. Data are represented as mean ± SEM, n = 3. P < 0.05 is considered significant, Mann–Whitney U test