PI3Kα-specific inhibitor BYL-719 synergizes with cisplatin in vitro in PIK3CA-mutated ovarian cancer cells

Figures

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  Fig. 1. PI3K inhibitors reduce the PI3K/Akt activity in ovarian cancer cells regardless the PIK3CA mutational status. (A) Western blot analysis of ovarian cancer cells SKOV-3, EFO-21 and OVCAR-3 treated with 1 or 10 µM of PI3Kα-specific inhibitor BYL-719 during 2h. DMSO is used as a control treatment. The levels of (B) P-Akt Ser473, (C) P-Akt Thr308, (D) p110α and (E) p110β are quantified and normalized with β-Actin. Mean +/− SEM (*p < 0.05, **p < 0.01, ***p < 0.001, n ≥ 3 independent biological replicates).

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  Fig. 2. PI3Kα-specific inhibitor BYL-719 and cisplatin synergistically reduce the number of ovarian cancer cells. (A) Ovarian cancer cells SKOV-3, EFO-21 and OVCAR-3 are cultured in 2D and are treated 1 day and 4 days after seeding with matrix combinations of PI3Kα-specific inhibitor BYL-719 and cisplatin for 7 days. The number of living cells is determined by MTT assay and the mean percentage of cell number inhibition is represented, compared to the control condition. Mean +/− SEM (n = 3 independent biological replicates). (B) A synergy score map is represented using SynergyFinder and the ZIP model with synergies identified with a synergy score above 5. (C) Ovarian cancer cells SKOV-3, EFO-21 and OVCAR-3 are cultured in 3D aggregates and are treated 1 day after seeding with matrix combinations of PI3Kα-specific inhibitor BYL-719 and cisplatin during 3 days. The number of living cells is determined by WST-1 assay and the mean percentage of cell number inhibition is represented, compared to the control condition. Mean +/− SEM (n = 3 independent biological replicates). (D) A synergy score map is represented using SynergyFinder and the ZIP model with synergies identified with a synergy…

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  Fig. 3. PI3Kα-specific inhibitor BYL-719 sensitizes 3D cultured cells to cisplatin cytotoxic effect. (A) SKOV-3 cells cultured in 3D aggregates are treated 1 day and 4 days after seeding with a fixed concentration of 1 µM of BYL-719 combined or not with increased concentrations of cisplatin (0.05, 0.5, 5µM). Living and dead cells are labelled with calcein and ethidium homodimer-1 respectively using the live and dead kit. (B) Living cells occupied area after treatment is quantified using ImageJ software. Mean +/− SEM (*p < 0.05, n = 3 independent biological replicates).

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  Fig. 4. PI3Kα-specific inhibitor BYL-719 in combination with cisplatin remain efficient in cell aggregates compacted by mesenchymal stem cells. (A) SKOV-3 GFP cells (green) associated with different MSC ratios (labeled in red using Quantum Dots) tumourospheres are performed and treated 1 day and 4 days after seeding with 1 µM of BYL-719, 5 µM of Cisplatin or a combination of both drugs. (B) Tumor cell aggregate area depending on the quantity of MSC is quantified using ImageJ software and is normalized to the condition with no MSC. (C) Tumor cell aggregate area after treatment is quantified using ImageJ software and is normalized to the control. CisPt stands for Cisplatin. Mean +/− SEM (*p < 0.05, **p < 0.01, ***p < 0.001, n = 3 independent biological replicates).