Effect of cellular reactive oxygen species on SK-N-MC Ewing sarcoma cells upon apoptosis induction by 2-Methoxyestradiol / 肿瘤研究与临床

ABSTRACT

Objective To explore the regulation of ROS level and ROS-triggered downstream events on SK-N-MC Ewing sarcoma cells upon apoptasis induction by 2-Methoxyestradiol (2-ME). Methods To detect the reversibility of apoptosis and the alternation of activity of respiratory chain, mitechondria transmembrane potential (△ψm), and cellular ROS level and to explore their association with flow cytometry, clark oxygen electronic node analysis, drug-removal design, and permeability transition (PT) pore stablizing agent. Results SK-N-MC cells were induced to ROS-dependent apoptosis. Apoptosis occured irreversibly after2-ME treatment for 3 h. Upon 2-ME treatment, the activity of respiratory chain was inhibited and the ROS generation was accelerated; the △ψm underwent the increasing within 3h but decreasing after 3h which could be reversed by PT pore stablizing; the ROS level underwent the continuous increasing and PT pore stablizing had no obvious effect on it. Conclusion 2-ME causes the acceleration of ROS generation via inhibiting the activity of respiratory chain and elevating the level of △ψm. ROS plays a signaling role and when total ROS accumulate to a threshold, the PT pore opening and the collapse of △ψm could be induced irreversibly and cell is eventually introduced to death.