The features of the development of radiation-induced oxidative stress in cancer cells with mutant TP53 gene

In this paper we attempt to examine the dynamic of accumulation of reactive oxygen and nitrogen, the intracellular concentration of glutathione in conjunction with the study of the dynamics of DNA damage in leukemia culture K562 cancer cells with non-active TP53 gene after exposure to radiation. The study was performed using cell. Intracellular concentration of active forms of oxygen, nitrogen, reduced glutathione and DNA damage were analyzed after 5, 15, 30 minutes and 1, 4, 8, 12, 24, 48 hours after irradiation of X-ray radiation at a dose of 4 and 12 Gy. Radiation-induced generation of ROS in K562 cells has two peaks with maximum ROS concentration, the first peak recorded after 30 minutes and the second 24 hours after exposure. Dynamics of DNA damage consists of three phases. The first phase is characterized by a significant increase in the number of DNA breaks and fixed in a 5 minutes after irradiation. There is a gradual decline in DNA damage during the second phase in period 1 – 8 hours after irradiation. DNA damage increases during 12 - 48 hours after irradiation (third phase). DNA damage is not associated with the processes of cell death. Dynamics of DNA damage coincides with the dynamics of oxidative stress development. DNA damage in the third phase may also be affected by nitric oxide, an increase which is observed in the period 8 - 48 hours after irradiation. Radiation exposure induces in K562 cells, carrying the defective gene TP53, genetic instability and permanent oxidative stress.