Expression of RBM3 in the cisplatin-sensitive A2780 ovarian cancer cell line compared to the cisplatin-resistant cell line A2780-Cp70 and the effects of cisplatin treatment on viability, cell cycle phase distribution and apoptosis in A2780 and A2780-Cp70 cell lines. (A) Immunocytochemical staining and (B) immunoblotting of RBM3 showing substantially lower RBM3 protein expression in the cisplatin-resistant A2780-Cp70 cell line compared to its parental cisplatin-sensitive A2780 cell line. (C) Relative mRNA expression was also reduced in the A2780-Cp70 cells compared to A2780 cells as shown by qRT-PCR analysis. Data shown are mean ± SEM of a representative experiment of two independent experiments performed in triplicate. (D) Cell growth illustrated as viability ratio 48:24 and 72:24 hrs measured by WST-1 demonstrating no difference between A2780 and A2780-Cp70 cells. Data shown are mean ± SEM of a representative experiment of three independent experiments performed in triplicate (E) Cell viability was evaluated by WST-1 assay in A2780 and A2780-Cp70 cells treated with cisplatin (1, 5, 10, 25, 50 and 100 μM) for 1 h followed by 48 hrs culture in fresh drug-free media. Data are presented as mean values from four independent experiments performed in triplicates presented as percentage of viable cells as compared with untreated cells. Error bars represent SEM. (F-G) A2780 and A2780-Cp70 cells were treated with 50 μM cisplatin for 1 h followed by 48 hrs culture in fresh drug-free media followed by flow cytometric analysis of (F) cell cycle phase distribution and (G) fraction of apoptotic cells. Data are presented as mean value from three independent experiments presented as fold change of cisplatin treatment. Error bars represent SEM.