EFFECT OF LASER IRRADIATION COMBINED WITH CHEMOTHERAPY ON EHRLICH CARCINOMA CELLS AND MACROPHAGES IN VITRO

Konovalenko S.V., Didenko G.V., Kruts O.O., Prokopenko I.V.

• R.E. Kavetsky Institute of Experimental Pathology, Oncology and Radiobiology of NAS of Ukraine, Kyiv, Ukraine

Existing approaches to lasers application in cancer treatment do not always lead to satisfactory or predictable results; therefore, this technique requires improvement. One of the possible options is the combined use of laser irradiation and chemotherapy. Aim: to study the effect of laser irradiation of different intensities in the mono mode on Ehrlich cancer cells and experimental animals’ peritoneal macrophages, as well as to assess the synergy of effects of light stimulation combined with low-dose chemotherapy on Ehrlich carcinoma cells. Objects and methods: Ehrlich ascites carcinoma cells and peritoneal macrophages of intact Balb/c mice were used in an in vitro study. The effect of lasers with a wavelength of 660 and 810 nm in the mono mode and in combination with doxorubicin was examined. Cells viability was assessed in a respiratory test; macrophage functional activity was assessed by exogenous peroxidase and nitric oxide (NO) production. Statistical analysis was performed according to the generally accepted methods of variation statistics using Origin 7.5 software. Results: evaluating the cytotoxic effect on Ehrlich carcinoma cells, it was found that the combined application of doxorubicin and infrared laser radiation (810 nm) is more effective compared with effects of each approach applied in the mono mode. The rate of cells’ respiratory activity under the influence of the laser in the mono mode was 0.122 ± 0.002 opt.u. compared to 0.18 ± 0.005 in the control (p ≤ 0.05). The combined application of doxorubicin and irradiation resulted in a significant (p ≤ 0.05) decrease in this indicator comparing with both the non-irradiated control and mono-mode irradiation. The stimulation of the peritoneal macrophages’ functional activity under the influence of lasers with a wavelength of 660 and 810 nm in the mono mode was detected. Conclusions: efficacy of combined application of small doses of doxorubicin with 660 nm or 810 nm laser irradiation was shown. Considering cytotoxic effects on Ehrlich carcinoma cells, the application of infrared (810 nm) laser irradiation combined with doxorubicin is a more promising combination.