Antitumor efficiencies of cytostatics dioxadet, cisplatin, mitomycin C, melphalan, and paclitaxel after a single intraperitoneal or intravenous injection in doses of 1.5, 4, 1.5, 2, and 5 mg/kg, respectively, were studied on the model of transplanted ovarian tumor in 124 rats. The antitumor effects were evaluated by the increase in median survival. Dioxadet, cisplatin, and melphalan injected intraperitoneally significantly prolonged the lifespan median - by 79, 88, and 114%, respectively, and were in fact ineffective, when injected intravenously. Intraperitoneal mitomycin C prolonged lifespan median by just 35%, intravenous - by 152%. Paclitaxel injected intraperitoneally and intravenously prolonged the lifespan median by 45 and 81%, respectively.

Background. Photodynamic Therapy is one of the treatment methods used in modern oncology. Evaluation of the efficacy in vivo of photosensitizers on tumor models is generally accepted, but the photodynamic  therapy technique in mice is not without drawbacks.The purpose of the study was evaluation of the efficacy of photodynamic therapy in mice with Ehrlich tumor model after subcutaneous and intracutaneous injection of tumor cells.Material and Methods. The study was conducted on BAL B/C mice of both sexes. Fotoditazin® and Radachlorin® were used as photosensitizers. For photoactivation, the Alod laser apparatus with a wavelength of 662 nm was used.Results. A comparison of photodynamic therapy with subcutaneous and intracutaneous localization of Ehrlich tumor was performed. It was shown that depending on the location and depth of inoculation of Ehrlich tumor, the pharmacokinetics (both the fluorescence intensity over time and the contrast ratio of the tumor/surrounding tissue) and pharmacodynamics (tumor growth inhibition, survival) of photosensitizers are significantly different. Higher contrast of the tumor/surrounding tissue is observed with intracutaneous localization of the tumor.Conclusion. A model with intracutaneous localization of Ehrlich tumor can be recommended for a primary assessment of efficacy; it allows the use of fewer animals in the experiment. When planning experiments to study photosensitizers and evaluating their results, the advantages and disadvantages of different methods for modeling tumors in mice should be taken into account.

Because of the high risk of brain metastases from HER2-positive breast cancer, the study of the anticancer activity of drugs used to treat brain tumors, in particular lomustine, is of great importance. In the FVB/N Her-2 transgenic mice bearing HER2-positive breast cancer (BC HER2+), a single oral administration of lomustine at a dose of 50 mg/kg resulted in a significant tumor growth inhibition (up to 96 %, p<0.0001). The tumor growth index (TGI) expressed as a ratio between the areas under the kinetic curves of tumor growth in the study and control groups and amounted to 33 % (p<0.001) indicated the high activity of lomustine. However, the effect of lomustine on intramuscularly transplanted Ehrlich tumor was insignificant (tumor growth inhibition and tumor growth index were <39 % and 68 %, respectively). Lomustine administered orally at a single dose of 50 mg/kg 24 hours after intracranial transplantation of BC HER2+ increased the median survival time up to 30 days in FVB/N mice compared to 21 days in the control group mice (p<0.001). The high therapeutic effect of lomustine in HER2-positive breast cancer mice is likely can be explained by the biological characteristics of this tumor; therefore clinical trials of lomustine for HER2-positive tumors are needed.

To study the mechanisms underlying the effects of intraperitoneal chemoperfusion and to develop the optimal chemoperfusion regimen, an animal model of peritoneal carcinomatosis closely resembles a human model of peritoneal carcinomatosis is required. In our study, the model of peritoneal carcinomatosis in rats with ascitic ovarian cancer was used. material and methods. There were three groups of rats with ascitic ovarian cancer: 1 – the control group (n=15) having no treatment; 2 – rats receiving normothermic intraperitoneal chemoperfusion with cisplatin, 40 mg/kg (n=12); 3 – rats receiving hyperthermic intraperitoneal chemoperfusion with cisplatin, 20 mg/kg (n=14). All animals were euthanized with subsequent autopsy. results. Ascitic ovarian cancer developed in 100 % of the animals injected with the tumor cells. The median overall survival of rats in the control group was 9.5 days. At autopsy, all rats had ascites, and rats surviving 15‒17 days after the tumor cell injection had white tumor nodes measuring 1–3 mm in the greater omentum, intestinal mesentery, parietal and visceral peritoneum. The nodes were histologically verified as metastases of low-differentiated ovarian tumor. In 2 and 5 rats from groups 2 and 3 respectively, metastases in paratracheal lymph nodes and tumor hydrothorax were detected with no evidence of peritoneal carcinomatosis. The median survival of rats in groups 2 and 3 was significantly higher than that in the control group, being 37.5 and 25.5 months, respectively (р=0,256). conclusion. This in vivo study proved that localization of ascitic ovarian tumor, development of the tumor in all animals injected with tumor cells, fast ascites progression and peritoneal carcinomatosis make this ascitic ovarian cancer an adequate preclinical model of peritoneal carcinomatosis to study intraperitoneal chemoperfusion. Further studies are needed to understand the reasons and mechanisms of the tumor hydrothorax development in rats after intraperitoneal chemoperfusion.