Role of FACT in response to cisplatin. A. Cisplatin-induced appearance γH2AX is SSRP1-dependent. SSRP1 or control (ctr) shRNA-expressing A2780 cells were treated with 100 μg/ml cisplatin for 0, 1 or 2 hrs. Using immunoblotting SSRP1 and β-actin were detected in whole cell lysates and γH2AX and H2A in chromatin fractions. B. FACT inhibition sensitizes cancer cells to cisplatin. SSRP1 and control shRNA-expressing A2780, MDA-MB-231 and HEK293T cells were treated with increasing concentrations of cisplatin. IC50 values at 24 hrs are shown. Results represent the mean ± s.e.m. of five independent experiments. For comparisons of control and SSRP1 depletion within cell lines, p < 0.01. C. Levels of cisplatin-induced PARP-1 cleavage after silencing SSRP1 expression in A2780 cells. SSRP1, PARP-1, and β-actin were analyzed in whole cell lysates of cells treated with 100 μg/ml cisplatin for 0, 4 or 6 hrs by immunoblotting.