Figure 3.

Drug-resistant HGSOC cells exhibit a remodeling of antioxidant systems. (A) Schematic representation of glutathione synthesis, recycling, and degradation. (B) Real-time RT-PCR analysis of indicated genes in platinum-resistant PEA1, PEO23, and PEO4 cells compared to their matched-sensitive counterparts PEA1, PEO14, and PEO1 cells. Data are expressed as mean ± S.E.M. of −ΔΔCt (log2FC) from four independent experiments with technical triplicates each. Numbers indicate the statistical significance (p-value), based on the Student’s t-tests performed on ΔCt values (significant values highlighted in red). (C) Total lysates obtained from cisplatin-sensitive and -resistant OC cells were separated by SDS-PAGE and immunoblotted with the indicated antibodies. Images are representative of three independent experiments. Bar graphs below each image represent densitometric quantification of bands, expressed as mean ± SEM (n = 3). Significance was assessed by Student’s t-test (* p-value < 0.05, ** p-value < 0.01). (D) Viability assays performed in PEA1 and PEA2 cells following TXNRD1 silencing and treatment with either cisplatin (20 µM and 40 µM, respectively) for 48h or H₂O₂ (20 mM) for 30 min. Data are expressed as mean ± SEM of four independent experiments, with technical triplicates each. Significance was assessed by Student’s t-test (* p-value < 0.05, ** p-value < 0.01, ns p-value > 0.05). The insert shows the degree of TXNRD1 silencing expressed as fold change compared to the respective control-directed siRNA transfected cells (n = 2).