CC BY
2*
ALT'23 The 30th International Conference on Advanced Laser Technologies
B-P-8
Cancer cells reaction to the exposure to UV-A and blue spectral regions radiation in the presence of antitumor drugs
V. Plavskii1, O. Dudinova1, L. Plavskaya1, A. Svechko1, A. Tretyakova1, A. Mikulich1, R. Nahorny1, A.
Sobchuk1, T. Ananich1, I. Leusenka1, S. Yakimchuk1, Le Hang Dang2, Ngoc Quyen Tran2
1-B.I.Stepanov Institute of Physics of the National Academy of Sciences of Belarus, Minsk, Belarus 2- Institute of Applied Materials Science Vietnam Academy of Science and Technology,
Ho Chi Minh City, Vietnam
v.plavskii@ifanbel. bas-net. by
The aim of this work is to study the response of cancer cells to the combined action of phytochromic anticancer drugs (curcumin, quercetin and apigenin), commonly used as chemotherapeutic agents in the treatment of cancer, and UV-A and blue radiation corresponding to their absorption spectrum. Confocal fluorescence microscopy studies of a suspension of cancer cells (HeLa cervical epithelioid carcinoma cells and C6 rat brain glioma cells) showed the ability of antitumor chemotherapeutic drugs to penetrate through the cell membrane and localize in individual compartments of the cancer cell. It has been shown that curcumin is predominantly localized in the area of cell membrane; quercetin is distributed throughout the cell and its predominant localization in the area of the cell membrane is not observed; apigenin is selectively localized in individual intracellular organelles, which is confirmed by the bright localized luminescence of individual areas of cells.
It has been established that all studied anticancer chemotherapeutic drugs under dark conditions have an inhibitory cytotoxic effect, which manifests itself in a decrease in the metabolic activity of cells (colorimetric MTT-test). A decrease in the metabolic activity of HeLa and C6 cancer cells also is caused by exposure to their suspension to optical radiation with wavelengths of A = 365, 405, or 440 nm at energy dose of D = 4.515 J/cm2. Damage of the cells by radiation of this spectrum region is due to the sensitizing effect of endogenous porphyrins and flavins localized in cells. The damaging effect of light depends on the radiation wavelength, energy dose and is confirmed by MTT-test, flow cytometry and chemiluminescence studies. It could be expected that with the combined action of anticancer drugs and light, a synergistic effect would be observed, which has been noted in a number of publications with other chemotherapeutic drugs. Indeed, the studies have shown that if under dark conditions curcumin in the concentration range of 1-5 ^M has an insignificant inhibitory effect on the metabolic activity of cells, then under the action of light A = 440 nm, D = 15 J/cm2, inactivation increases by 5 times. According to flow cytometry data, such irradiation of cells increases their proportion by 4 times at the stage of necrosis and late apoptosis. Therefore, the main reason for the decrease in the metabolic activity of cells is a lethal outcome. The effect is realized due to photodynamic processes sensitized by curcumin. Moreover, in the studied photochemical process a decisive role is played by hydrogen peroxide, the formation of which is initiated by the generation of singlet oxygen by curcumin during its photoexcitation. Other results have been obtained when cells are exposed to A = 365 nm radiation in the presence of apigenin and quercetin. It has been shown that these drugs do not have sensitizing properties; quercetin exhibits antioxidant properties even at low concentrations. This is confirmed by the data of chemiluminescent studies, as well as by a decrease in the rate of cell inactivation initiated by exposure to radiation A = 365 nm, when quercetin is added to their suspension before irradiation. During the chemiluminescence control, apigenin does not show antioxidant properties. However, it has turned out that the exposure to radiation with A = 365 nm, D = 4.5 J/cm2 on HeLa cells in the presence of 1-20 ^M of apigenin almost protects them from the inactivating effect of the indicated phytochrome agent. Exposure to light of the same parameters on cells in the presence of quercetin leads to an evidential stimulation of the metabolic activity (survival) of tumor cells compared to the dark variant. Moreover, the magnitude of the stimulating effect increases with an increase in the concentration of the anticancer drug, which can be explained by its antioxidant properties. The protective role of phytochromic preparations photoproducts formed in the course of irradiation in respect to cells is also not excluded.
