PI3K Inhibition Sensitize the Cisplatin-resistant Human Ovarian Cancer Cell OVCAR3 by Induction of Oxidative Stress

Background: This study evaluates the effect of simultaneous AKT inhibition and cisplatin therapy in
changes of Reactive Oxygen Species (ROS) production, apoptosis induction, and cell survival in cisplatinresistant
OVCAR3 cell.
Methods: OVCAR3 cancer cells were treated with cisplatin, Ly 294002 (LY), and cisplatin+Ly to
investigate the cytotoxicity effect of the mentioned groups via MTT assay. Then, DCFH-DA (2′, 7′-
dichlorodihydro fluorescein diacetate) assay kit is used to assess the potential of treated groups in
intracellular ROS generation. Protein expression levels of caspase-3, cleaved caspase 3, PI3K, Akt, p-Akt,
XIAP, and Survivin are estimated through immunoblotting assay in all three experimental groups.
Results: The results showed that all three treated groups, including cisplatin and Ly alone and coadministration
of cisplatin+Ly, could reduce the cell vitality of OVCAR3 cancer cells, induced intracellular
production of ROS and increased the expression level of activated caspase 3 and Akt protein, whereas downregulated
the phosphorylation of Akt protein. However, the effect of combination therapy was more tangible
compared to single therapy and control groups. In contrast, the expression amount of XIAP, Survivin, and
PI3K did not show detectable changes in comparison with the control group.
Conclusions: The results showed that the AKT inhibition by Ly could sensitize the OVCAR3 cancer
cells to the cisplatin and lower the effective dose of cisplatin through hyperactivation of oxidative stress.