Fig. 4

Evaluation of Cisplatin and CIGB-300 combined treatment in a chemo-resistant setting. a A549 and A549-cispR cells were treated with low-lethal doses of CIGB-300 (150 μM) and/or Cisplatin and cell number was assessed 72 h later. Viability values were compared to those obtained in both cell lines without treatment, which were set as 100%. Data represent the mean ± SE of three independent experiments. *p < 0.05 vs. the parental cell line (one-way ANOVA test). b Chou and Talalay combination index (CI) plot for CIGB-300 and Cisplatin values of three independent experiments. c A549 and A549-cispR cells were treated with a high dose of CIGB-300 (300 μM) during 72 h and cell viability was evaluated using the MTS assay. Viability values were compared to those obtained in both cell lines without treatment, which were set as 100%. Data represent the mean ± SE of three independent experiments. *p < 0.01 vs. the parental cell line (Student’s t test). d A549 and A549-cispR cells were treated with a high dose of CIGB-300 (300 μM) during 18 h and apoptosis induction was visualized by an acridine orange/ethidium bromide double staining assay. Figure shows representative images of three independent experiments (left side). The number of dead cells was quantified and expressed as a percentage of the total cell number for each cell line (right side). Data represent the mean ± SE of three independent experiments. *p < 0.05 vs. the parental cell line (Student’s t test). e A549 and A549-cispR cells were treated with 150 μM of CIGB-300 for 90 min in the presence or not of cisplatin. PMA was used as control. Nuclear extracts were prepared, resolved in 10% SDS-PAGE and blotted with anti p65/RelA antibodies (50 μg protein/lane). ACTIN expression level was used as protein loading control. Results are representative of three independent experiments. f Whole cell extracts prepared from A549 and A549-cispR cells treated with 300 μM of CIGB-300, were resolved on 10% SDS-PAGE and blotted with BAX and c-MYC antibodies (50 μg protein/lane). ACTIN expression level was used as protein loading control