MORPHOLOGICAL STUDY OF HUMAN U-87 MG GLIOBLASTOMA SUBCUTANEOUS XENOGRAFTS AFTER LOCAL IRRADIATION BY EPITHERMAL NEUTRONS

Currently, boron neutron capture therapy is increasingly used to treat malignant tumors. This method is effective against radioresistant tumors and neoplasms that are poorly amenable to traditional treatment methods, but the issue of increasing its effectiveness remains highly relevant. The aim of the study was to study the structure of subcutaneous xenografts of human glioblastoma U-87 MG after local irradiation with epithermal neutrons and/or against the background of treatment with boron-containing substances - borocaptate and boron phenylalanine. Sixty immunodeficient SCID mice with heterotopic xenografts of human glioblastoma U-87 MG cells were used. It was found that after the therapy in all groups of animals by the 7th day there was a decrease in the tumor mass compared to the control group, by the 14th day this indicator was also slightly lower and only the combined administration of borocaptate and boronophenylalanine followed by irradiation led to a reliable decrease in this indicator by 31% (p<0.01). The volumes of the tumor node by the 7th day were 2 times higher than the initial indicators, by the 14th day the growth of the tumor volume decreased on average by 1.25 times in all the studied groups. The most noticeable morphological changes compared to untreated animals were noted in the group of animals that received both boron preparations followed by irradiation with epithermal neutrons. They had a decrease in the proliferative activity of tumor cells and the number of blood vessels, the foci of necrosis were smaller, as were the tumor nodes in general. The obtained data indicate that the methods of animal treatment used cause therapeutic pathomorphosis, but are not able to completely stop tumor growth. The most pronounced effect obtained in the case of using two drugs in combination with subsequent irradiation with epithermal neutrons indirectly indicates their possible synergistic effect, most likely due to an increase in the total dose of boron in tumor cells.

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