Fig. 5: SFRS2-mediated p53 and its phosphorylation at Serine 15 is required for PANDAR-regulated cisplatin sensitivity.

a CCK-8 assay of cell viability in HO-8910PM-PANDAR cells after treated with indicated doses (1–40 μM) of cisplatin for 24 h with or without SFRS2 knockdown (shSFRS2). Cell survival rate was calculated through three independent experiments. b Cell survival rate and the subsequent half maximal inhibitory concentration (IC50) were calculated from a using GraphPad 6.2 software. c QRT-PCR assay of PANDAR expression in HO-8910PM-PANDAR cells with or without SFRS2 knockdown (shSFRS2). d Protein expression performed with western blotting assay showing an increased level in p53, phosphor-p53 at Ser15 and -Ser20 in A2780 and HO-8910PM cells with SFRS2 knockdown (shSFRS2). e Protein expression levels of SFRS2, p53, phosphor-p53 at Ser15 and Ser20 in HO-8910PM-PANDAR cells with or without SFRS2 knockdown (shSFRS2) after 0 or 30 μM cisplatin treatment for 5 h. Non-treated cells serve as controls. f Proteins expression in total and nuclear fractions from A2780 and A2780-DDP cells with PANDAR knockdown (shPANDAR1, shPANDAR2) after treated with cisplatin for 12 h. H3 protein serves as nuclear control. g Cell viability via CCK-8 assay in A2780-DDP-PANDAR knockdown (shPANDAR) cells with or without p53 silenced after treated with indicated doses (0–40 μM) of cisplatin for 24 h. h Colony formation and accordingly quantification in A2780-DDP-PANDAR knockdown (shPANDAR) cells with or without p53 silenced after incubated with cisplatin for 10 days. i Apoptosis measurement in A2780-DDP-PANDAR knockdown (shPANDAR) cells with or without p53 silenced after incubated with 20 μM cisplatin for 24 h. j QRT-PCR assay of PANDAR expression in A2780-DDP-PANDAR knockdown (shPANDAR) cells with or without p53 silenced. Control groups are normalized to 1. Data presents the mean ± S.D. *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001, two-tailed Student’s t-test. n = 3 independent experiments