Fig. 2: USP10 stabilizes PARP1 and positively correlates with PARP1 expression in breast cancer.

A HEK293 cells overexpressing Flag-USP10 were subjected to western blot analysis to determine PARP1 expression levels. B PARP1 levels were determined in MCF7 cells that were transfected with three different siRNA-USP10 target sequences for 48 h. C PARP1 levels were determined by western blot analysis of cell lines with or without USP10 knockdown. D PARP1 levels were determined in MCF7 cells treated with or without USP10 inhibitor (Spautin-1) for 24 h at the indicated concentrations. E HEK293 cells were co-transfected with Flag-PARP1 and Myc vector, Myc-USP10 or Myc-USP10 C424A plasmids for 48 h, followed by western blot analysis with anti-Flag or anti-Myc antibodies. F Flag-PARP1 protein levels were assessed at different time points following CHX (20 μM) treatment of HEK293 cells co-transfected with Flag-PARP1 and Myc vector, Myc-USP10 or Myc-USP10 C424A plasmids for 48 h. G PARP1 protein levels were assessed at different time points following CHX (20 μM) treatment of HEK293 cells with or without USP10 shRNA-mediated knockdown. H USP10 and PARP1 protein levels were assessed in seven representative cancer specimens. ‘N’ represents normal tissue, and ‘T’ represents tumor tissue. I Representative sections and semiquantitative analyses of USP10 expression in breast cancer tissue (n = 30). Data are expressed as mean ± SEM. **P < 0.01 (Mann–Whitney test). J Representative sections and semiquantitative analyses of PARP1 expression in breast cancer tissue (n = 30). Data are expressed as mean ± SEM. ***P < 0.001 (Mann–Whitney test). K Expression of USP10 and PARP1 are positively correlated in consecutive sections of breast cancer tissue. The results of Spearman correlation analyses of P value and correlation coefficient are shown.