Cellular mechanisms of the response of Hela Kyoto tumor cells to the complex effects of photobiomodulation and ionizing radiation at doses used in clinical practice.

Abstract

One of the promising methods for protecting normal tissues during radiotherapy is photobiomodulation (PBM, low-level laser therapy); however, there is evidence of a positive effect of PBM on tumor cells. Therefore, it is crucial to evaluate the potential effects of PBM in combination with ionizing radiation (IR) on tumor cells.
The aim of this study was to investigate the mechanisms of cellular response of HeLa Kyoto tumor cells to the combined exposure of clinically significant doses of ionizing radiation and low-intensity red laser light. The adaptive (PBM + IR) and stimulatory (IR + PBM) effects of low-intensity laser light were examined.
Cell irradiation with IR was performed on a Novalis Tx linear accelerator (beam energy of 6 MV). The exposure of cells to low-intensity red light was carried out with a fluence of 0.3 J/cm² at a wavelength of λ = 640 nm. In this study, the combined effects of PBM before and after IR exposure at doses of 2 Gy, 4 Gy, and 6 Gy on the cell cycle, mitochondrial potential, and cell death of HeLa Kyoto tumor cells were investigated. Experiments were conducted using a FacsAriaIII flow cytometer.
It is presumed that the combined effect of ionizing radiation and photobiomodulation in the sequence of IR + PBM has a stimulatory effect on tumor cells, particularly through the regulation of the cell cycle, indicating the potential effects of PBM on DNA repair. Furthermore, the results suggest that IR + PBM may protect cells from apoptotic death by favorably influencing the oxidative-reduction state of the mitochondria.

Speaker

Artem Olegovich Belotelov
The National Research State University of Nizhny Novgorod named after N.I. Lobachevsky
Россия

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