The problem of elaboration of methods for effective mobilization of immune antitumor processes remains urgent. Earlier, it was shown that regression of experimental animal tumors can be achieved under the influence of low-intensive electromagnetic radiations (EMR) and magnetite nanoparticles (NPs) (Garkavi L.H. et al, 1996; 2013).The aim of the study was to determine the possibility of regression of large transplanted tumors of white rats under the influence of low-intensity EMR of millimeter range (EHF) and magnetite NPs.
In experiments on 123 white outbred male rats (200-300g) with transplanted Pliss lymphosarcoma - low-intensity EMR EHF (42.2 GHz, 10 mW/cm2, exposure 15-30 min, low-frequency modulation) and magnetite NPs (10 ± 2 nm) in the form of the magnetic fluid AM-01 (“AM-Cube”, Ekaterinburg) were used. The EMR acted on the animal's head starting 3 days before the tumor was transplanted. NPs were injected into peritumoral zone 2-3 times a week in a single dose of 17.7 mg/kg to animals with already formed tumors. Duration of treatment was 4 weeks. We studied the dynamics of tumor size, histochemical and cytometric changes in tumor tissue. The Wilcoxon test was used to evaluate the results.
When EMR EHF was used, complete regression of tumors with a size of 5-6 cm3 and a partial regression (by 30-40%) of tumors with a size of 10-13 cm3 were noted. The effect was obtained in 33% of the animals. In cases of using of magnetite NPs, tumor regression was observed in 40% of the animals, complete regression of tumors with a size of 5-30 cm3 was observed. Before the regression began, the tumor growth rates did not differ from those in the control group when using as one as the other factor. In addition, the regression was characterized by a rapid rate (5-7 days) and no signs of intoxication in animals. In the peritumoral area considerable macrophage activity and increasing number of cytotoxic T-lymphocytes were noticed.
The timing of the onset of regression, its dynamics and the absence of signs of intoxication during rapid elimination of large tumors indicated the deployment of antigen-presentation processes and specific killing of tumor cells by inducing apoptosis.
Clinical trial identification
Legal entity responsible for the study
Rostov Research Institute of Oncology, Ministry of Public Healthcare of the Russian Federation
Rostov Research Institute of Oncology
All authors have declared no conflicts of interest.