CYTOMORPHOLOGICAL CHANGES IN MCF7-DOX CELLS AND THEIR CORRELATION WITH THE ACTIVITY OF THE CELL CYCLE REGULATOR P21 AFTER COMBINED EXPOSURE TO INFRARED LASER AND DOXORUBICIN

Abstract

Introduction: In recent years, studies of infrared laser irradiation effect on tumor cells in combination with various chemotherapeutic agents have been developing dynamically. Objective: To study the effect of infrared laser in combination with low doses of doxorubicin on cytomorphological characteristics of MCF-7DOX culture cells and p21 expression level. Materials and Methods: MCF-7DOX tumor cells were cultured in DMEM medium with 10% fetal calf serum (FCT) and 40 μg/ml gentamicin. Doxorubicin was added to the cells to a final concentration of 2 μg/ml and 0.5 μg/ml. Cells were irradiated with infrared laser (Fotonika-Plus, Ukraine) with a wavelength of 810 nm (irradiation time — 5 min, power density — 50 mV/cm², irradiation dose 15 J/cm²). Photomicrographs of cells were taken using a Carl Zeiss microscope, Germany. An immunocytochemical study was also conducted using monoclonal antibodies to the factor p21 (Thermo Scientific, USA). Results: The evaluation of morphological characteristics in micropreparations testifies to the antitumor effectiveness of the combined effect of infrared laser irradiation and doxorubicin. It is noteworthy that the cytotoxic effects of chemotherapy in combination with photobiomodulation were observed when using different doses of doxorubicin: 2 μg/ml and 0.5 μg/ml. When studying the biological activity of cells using immunocytochemistry, it was established that the combination of doxorubicin and infrared laser irradiation led to an increase in the expression of p21, and it is important to note that a similar effect was observed at both concentrations of doxorubicin: as at 2.0 μg/ ml and 0.5 μg/ml. The simultaneous destructive effect on tumor cells and the increase in p21 expression allows us to make a preliminary cautious assumption that the proposed technique of combination of infrared laser irradiation with doxorubicin determines the effect of the p21 factor in the role of a tumor suppressor. Conclusions: The results of the study allow us to consider the use of doxorubicin in combination with infrared laser as a promising method of cytotoxic effect on tumor cells.