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Purpose of the study. Evaluation of the expression of immunohistochemical tumor markers Ki-67, b-catenin, Bcl-2, P53, connexin 32 and connexin 43 when using 2-(6,8-dimethyl-5-nitro-4-chloroquinoline-2-yl)-5,6,7-trichloro-1,3-tropolone in mice with xenographs of squamous cell lung cancer.Materials and methods. Subcutaneous PDX models of human squamous cell lung cancer were created in immunodeficient BALB/c Nude mice. A fragment of the patient’s tumor (3 × 3 × 3 mm) was implanted subcutaneously in the right thigh of a previously anesthetized mouse. 200 μl of 2-(6,8-dimethyl-5-nitro-4-chloroquinoline-2-yl)-5,6,7-trichloro-1,3-tropolone was administered orally using a probe in 12 doses once every 3 days. All animals were divided into groups depending on the tropolone doses: experimental groups 2–5 with doses of 0.0055, 0.055, 0.55 and 2.75 mg/g, respectively. The control group received 1 % starch gel which was tropolone carrier. The animals were euthanized 36 days after the start of the substance administration, and the tumor tissue was isolated and prepared for the IHC study according to the standard protocol. IHC reactions were performed using antibodies for Ki-67, b-catenin, Bcl-2, P53, connexin 32 and connexin 43.Results. Higher tropolone doses were associated with decreased expression of Ki-67, b-catenin, and the Bcl-2 protein, but increased expression of the P53 protein. The dosage of tropolone and expression of connexin 43 were directly proportional.Conclusion. Immunohistochemical analysis of expression of proteins in PDX models of human squamous cell lung cancer when using 2-(6,8-dimethyl-5-nitro-4-chloroquinoline-2-yl)-5,6,7-trichloro-1,3-tropolone showed the changes indicating its antitumor efficacy and suggesting a possible mechanism of action based on the activation of apoptosis.

Purpose of the study. Evaluation of the antioxidant status and DNA damage in tissues of subcutaneous xenografts of non-small cell lung cancer and in peritumoral tissues created using the A549 and H1299 cell cultures.Materials and methods. The study included 35 intact male Balb/c Nude immunodeficient mice. Cell lines A549 and H1299 were used as transplantable tumor biomaterial. A CDX model was created in accordance with the protocol for supratentorial injections (Ozawa T., James C. D., 2010) adapted for this experiment. Growth rates were controlled and intracranial xenografts were visualized using a high-resolution micro-CT system. The activity of catalase and superoxide dismutase was determined with non-denaturing electrophoresis in 8 % and 12 % polyacrylamide gel. The concentrations of sulfhydryl groups were determined according to Ellman. The DNA damage in lymphocytes was determined by the comet assay.Results. The experiment resulted in the creation of models of brain tumors characterized by intracranial growth pattern in 100 %. The activity of catalase in the studied lysates of intracranial xenografts, peritumoral tissue and healthy tissues of tumor-bearing animals in all experimental groups increased statistically significantly relative to the healthy tissue of intact animals, and the greatest differences from the control were recorded in the group of animals with implanted H1299 culture at a concentration of 1 × 106 . Superoxide dismutase activity in the studied lysates of intracranial xenografts and peritumoral tissues statistically significantly increased compared to the control sample in all experimental groups. The highest increase in the SOD activity was observed in the tissues of intracranial xenografts with the highest tumor load, which amounted to 28.8 % and 32.9 % of the changes relative to the control sample. A statistically significant increase in the concentration of SH-groups relative to the control sample in tumor tissue lysates was revealed in all experimental groups, and the highest concentration (36.2 ± 0.47) was observed in the group of experimental animals with the highest tumor load. Percentage change in tail moment (DNA damage indicator) in groups O1, O2, O3 and O4 increased statistically significantly compared to the control sample by 55.8 %, 111.8 %, 97.3 % and 170 %, respectively.Conclusions. The observed increase in the activity of the antioxidant defense system, accumulation of oxidative modifications of proteins, and an increase in DNA double-strand breaks in the tissues of intracranial xenografts of non-small cell lung cancer in vivo suggest that the created models reflect processes similar to those in tumors of human non-small cell lung cancer.

Purpose of the study. The investigation is aimed to provide a systematic comparison of different contrasting methods for in vivo micro-CT diagnostic of orthotopic colorectal cancer models extracted by ortotopic implantation into the caecum of immunocompromised mice BALB/c Nude lines.Materials and methods. BALB/c Nude (N = 25) female mice were implanted by transplanted human colorectal cancer strain into the cecum. 20 days after the implantation mice were administered with iodine-based contrast agent Optiray by means of different administration method (intravenously, per os, intraperitoneally, per rectum) and micro-CT scans have been registered via Quantum GX2 tomograph. Measurement of tumor nodes was performed both by means of estimation from micro-CT images via RadiAnt DICOM Viewer software and by means of explicit measurements using calipers upon laparotomy and posthumously. At the last stage of the study, the animals were euthanized by cervical dislocation. The tumors were excised, measured with a caliper and placed in 10 % formalin for the standard histological analysis according to the standard methods.Results. The average volumes of tumor xenografts in animals with intravenous, oral, and intraperitoneal contrast administration measured at micro-CT were 53.7 ± 5.2 mm3, 52.7 ± 6.4 mm3 and 63.6 ± 5.6 mm3 respectively; measured at laparotomy – 43.0 ± 5.5 mm3, 44.5 ± 5.4 mm3 and 58.5 ± 5.5 mm3 respectively; measured post-mortem – 55.2 ± 6.6 mm3, 53.2 ± 8.8 mm3 and 65.9 ± 3.8 mm3 respectively. The average volumes of tumor xenografts isolated post-mortem in these groups were comparable with the values shown at micro-CT, but larger than the volumes measured at laparotomy.Conclusion. The results obtained demonstrated that intravenous, peroral and intraperitoneal administration techniques provide the best visualization of laboratory rodents pathological tissue upon in vivo micro-CT diagnostics and thus are preferred.

Experiments with small laboratory animals are required for better understanding of a disease flow, for studying the mechanisms of it’s development and for the development of new therapeutic strategies. A significant part of experimental studies involve anesthesia. In this regard, the choice of the optimal anesthesia protocol is an important point of research, since an inadequate depth of anesthesia or the influence of undesirable factors can lead to death; the type, duration, and goals of the procedure should be also taken into account.We have aimed to find out what has changed in anesthesia of laboratory animals lately, which drugs are currently relevant and what is the reason for their popularity.Anesthesia of mice is challenging for several reasons: animal size, metabolic rate, and high risk of hypothermia and hypoglycemia. In addition, anesthetics affect physiological parameters and therefore even more affect the results of experiments. At the moment, there is a large list of drugs used in laboratory animals. Since they are divided into groups depending on the routes of administration, we selected the following drugs from a number of articles: injectable anesthetics (medetomidine, dexmedetomidine, zoletil‑100, ketamine, xyla, propofol) and inhalation anesthetics (isoflurane, sevoflurane). Advantages and disadvantages of the drugs and their combinations were studied and described.An analysis of the literature showed that injection anesthesia is considered the main method of anesthesia for experimental animals and is relatively well tolerated by animals; it also does not require additional bulky equipment and additional staff qualifications, there are antagonists for a number of drugs, and is also affordable.In the majority of studies inhalation anesthesia was used in long-term complex manipulations/operations, since it is more manageable, agents require minimal metabolism, and in some cases do not require additional sedation.

The aim. To study the toxicity of 2-(6,8-dimethyl-5-nitro-4-chloroquinoline-2-yl)-5,6,7-trichloro-1,3-tropolone in vitro and in vivo.Materials and methods. 2-(6,8-dimethyl-5-nitro-4-chloroquinoline-2-yl)-5,6,7-trichloro-1,3-tropolone was synthesized using a method for expanding the o-quinone cycle during the reaction between 5-nitro-2,6,8-trimethyl4-chloroquinoline and 3,4,5,6-tetrachloro-1,2-benzoquinone while boiled in dioxane. An in vitro experiment was carried out in the human A549 cell line. Cell viability was assessed using the MTT colorimetric assay by reducing the optical density of the experimental samples compared with the control ones. Acute toxicity was studied on 20 BALB/c Nude male mice. The test compound was administered once orally as a suspension in 1% starch gel at three doses: 0.0055 (group 1), 0.055 (group 2) and 0.55 mg / g (group 3). The control group (group 4) received a placebo.Results. We synthesized a new compound, 2-(6,8-dimethyl-5-nitro-4-chloroquinoline-2-yl)-5,6,7-trichloro-1,3-tropolone. Its structure was established by 1 H nuclear magnetic resonance (NMR), infrared (IR) spectroscopy, and mass spectrometry. The yield was 19.8 g (52%), the melting point was 205–207 ºС, bright yellow crystals (benzene) were observed. The half-maximal inhibitory concentration (IC50) of 2-(6,8-dimethyl-5-nitro-4-chloroquinoline-2-yl)-5,6,7-trichloro-1,3-tropolone was 0.21 ± 0.01 μM, which was significantly lower (р < 0.05) than the IC50 of cisplatin (3.84 ± 0.23). Following the in vivo experiment, no toxic effect of tropolone was detected when administered once at a dose of 0.0055, 0.055, and 0.55 mg / g. Conclusion. 2-(6,8-dimethyl-5-nitro-4-chloroquinoline-2-yl)-5,6,7-trichloro-1,3-tropolone demonstrated cytotoxic effects on the A549 cell line at a lower IC50 than cisplatin which is widely used in treatment of cancers, including lung cancer. Insolubility of 2-(6,8-dimethyl-5-nitro-4-chloroquinoline-2-yl)-5,6,7-trichloro-1,3-tropolone in water and the absence of its toxic effect in the studied modes determine the scope of its application for further study of cumulative and antitumor effects.

Purpose of the study. Was was the creation of a Patient Derived Xenograft (PDX) model of non‑small cell lung cancer in immunodeficient mice adapted to growth in immunodeficient mice.Materials and methods. The study was performed using the tumor material from 14 donors implanted subcutaneously to 132 immunodeficient Balb/c Nude mice. Xenografts were maintained until the third passage. PDXs in the third passage from 3 patients were used to assess the model sensitivity to cisplatin. A histological analysis and genetic tests for the presence of EGFR mutations were performed for donor tumors from 3 patients and the corresponding xenografts in the third passage.Results. We observed a noticeable PDX growth already on the 8th day after the tumor material implantation. Successful xenograft engraftment was noted in 21 of 42 mice (50 %), which were rather successful results. A comparative histological analysis of tumor material from 3 patients showed that the PDX models retained the original histotype. We also demonstrated the identity of the EGFR mutations in the established xenografts from 3 patients and the donor tumors, which proved the value of these PDX models for preclinical studies of substances with potential antitumor activity. The analysis of the xenograft sensitivity to cytostatic cisplatin showed a statistically significant decrease in the growth rate in the xenografts obtained from 2 out of 3 patients, in comparison with the control.Conclusions. The created PDX models can be recommended as test systems for preclinical studies of the effectiveness of new pharmacological substances with potential antitumor activity.

Purpose of the study. Was to reveal the antitumor effect of 2‑(6,8‑dimethyl‑5‑nitro‑4‑chloroquinoline‑2‑yl)‑5,6,7‑trichloro‑1,3‑tropolone in subcutaneous PDX models of human lung cancer.Material and methods. The studied tropolone was synthesized using a method of expanding the o‑quinone cycle. Assess to it’s toxic effects was given by the survival and changes in the health status of female Balb/c Nude mice. Antitumor tropolone effects were studied in subcutaneous patient‑derived xenograft (PDX) models of human squamous cell lung cancer in Balb/c Nude mice. The average volumes of tumor nodes and tumor growth inhibition (TGI %) rate were taken into account. Biochemical blood tests and histological analysis of the tumor material were performed in recipient mice.Results. An analysis of acute tropolone toxic effects did not reveal the lethal dose. The maximal TGI was observed on day 36 of the experiment in group 5 which have received 2.75 mg/g tropolone and accounted 73.5 % for females and 74.4 % for males. The average tumor volumes in females of this group were 431.3 ± 1,1 mm3 on day 33 of the experiment, in males – 428.9 ± 1,7 mm3 on day 30, and then the tumor volumes declined. The biochemical analysis of blood and histological examination of the tumor tissue of recipient mice reflect the severity of the antitumor effect on the dose of the studied tropolone.Conclusion. The research demonstrated the antitumor activity of 2‑(6,8‑dimethyl‑5‑nitro‑4‑chloroquinoline‑2‑yl)‑5,6,7‑trichloro‑1,3‑tropolone against subcutaneous PDX models of human NSCLC. The revealed tendencies can be used to search for effective modes of the compound application in clinical practice.

Purpose of the study. Evaluation of the effect of the benzimidazole derivative dihydrobromide‑2-(3,4‑dihydroxyphenyl)- 9‑diethylamino-ethylimidazo-[ 1,2‑a] benzimidazole (RU‑185) on the growth of Lewis lung epidermoid carcinoma and B16-F10 melanoma when administered intragastrically.Materials and methods. For the experiment, we used female C57Bl/6j mice, which were inoculated subcutaneously with syngeneic tumors: Lewis lung carcinoma (LLC) and B16-F10 melanoma. RU‑185 was administered intragastrically to animals in a volume of 0.3 ml for 10 days, 1 time per day. For both tumors, depending on single doses of the substance for administration, groups were divided: 1st and 4th – 50 mg/kg, 2nd and 5th – 220 and 3rd and 6th – 500 mg/kg. The control groups were injected intragastrically with physiological saline in the same volumes and according to the same scheme. The following parameters were assessed: tumor volume, increase in life expectancy (T/S, %) and tumor growth inhibition index (TGI, %).Results. For animals with LLC in the 2nd group there is an increase in the indicator of life expectancy (T/S 162.3 %), and in the 3rd group there is a tendency to an increase in the T/S indicator. On the 1st day after the end of treatment in the 2nd and 3rd groups TGI was 73.0 % and 30.1 %, respectively (р < 0.05). On the 7th and 14th days after the end of the use of RU‑185 in the 2nd and 3rd groups the volume of tumors is 3.5 and 1.4 times less (on the 7th day) and 2.3 and 1.3 times (on the 14th day), respectively than in the control group (р < 0.05). At a dose of 220 mg/kg, complete regression of LLC tumors was shown in 20 % of animals.With the growth of B16-F10, the life expectancy of all groups did not differ. Intergroup differences in the dynamics of tumor growth are provided. Highlighted changes were found in the 5th group (on the 14th day after the end of the administration of RU‑185, TGI was 48.7 %).Conclusion. The investigated chemical substance dihydrobromide‑2-(3,4‑dihydroxyphenyl)-9‑diethylamino-ethylimidazo- [1,2‑a] benzimidazole showed antitumor efficacy against syngeneic tumors: Lewis lung epidermoid carcinoma and B16-F10 melanoma when administered intragastrically which leads to further testing of RU‑185 as a potential drug for the treatment of malignant neoplasms.

Purpose of the study. Was to analyze antitumor efficacy of the XAV 939 Wnt signaling pathway inhibitor and its combination with 5 fluorouracil in subcutaneous xenografts derived from patients with colorectal cancer.Materials and methods. Antitumor efficacy of the agents and their combination was studied in xenografts derived from patients with colorectal cancer and subcutaneously implanted in immunodeficient Balb/c Nude mice. All animals with tumors were divided into 4 groups (n = 5): group 1 received 5 fluorouracil 25 mg/kg, group 2 – XAV 939 25 mg/kg, group 3–5 fluorouracil and XAV 939 combination at the same dosages, group 4 was control. Criteria for the efficacy of the tested agents and their combination included tumor growth rate and tumor growth inhibition rate (TGI %).Results. The mean volumes of xenografts and tumor growth rate in the group receiving a combination of 5 fluorouracil and XAV 939 were 335.2 ± 40.7 mm3 , being lower than the averages of xenografts in controls – 609.3 ± 69.5 mm3 (p < 0.05). The mean volumes of xenografts in the group receiving 5 fluorouracil monotherapy were 601.9 ± 45.5 mm3 , in the group with the XAV 939 monotherapy – 527.9 ± 258.6 mm3 . The highest TGI (44.99 %) was registered in the group receiving a combination of 5 fluorouracil and XAV 939.Conclusion. The study revealed the ability of combined XAV 939 Wnt signaling pathway inhibitor and 5 fluorouracil to inhibit the growth of subcutaneous xenografts derived from patients with colorectal cancer.

The issue of factors that modify the tumor process stays relevant. The effect of unilateral sciatic nerve ligation on the growth of Guerin's transplantable carcinoma and the lifespan of white outbred rats of the same age, which differed in adaptation status and aging rates, was studied.Material and Methods. The motor activity (open field test), the character and tension of the general nonspecific adaptional reactions of the body (AR) according to Garkavi–Kvakina–Ukolova, the dynamics of tumor sizes and the lifespan of rats after Guerin’s carcinoma transplantation were evaluated.Results. The effect of unilateral sciatic nerve ligation differed from the unidirectional negative effects known in tumor-bearing animals after bilateral ligation of the sciatic nerve. In groups with unilateral ligation of the sciatic nerve and a false operation, more than 40 % of animals showed an increase in lifespan compared with the maximum lifespan in the control group. At the same time, in the most cases, the tumor growth rate was similar to the control indicators or exceeded them (more 25 % of cases). A temporary inhibition of tumor growth was observed only in individual animals. There was no direct relationship between tumor growth or lifespan and the degree of decrease in the motor activity of animals 4 weeks after nerve ligation. A correlation between the changes in the ARs and lifespans of animals and, to a lesser extent, the dynamics of tumor growth was observed. The distinct negative effect of increased aging rate, measured by animal weight, on tumor development and lifespan in studied rats was shown, but not in the cases of sciatic nerve ligation. Unilateral sciatic nerve ligation had a multidirectional effect on tumor growth and lifespan in rats with different rates of aging, depending, probably, on the individual pain sensitivity and the individual features of systemic regulation of tumor-bearing animals.Conclusion. The results reflect the complex relationship between processes associated with chronic pain, oncogenesis, aging and features of neuroendocrine and immune regulation of experimental animals. The question of the reasons for the preservation of viability in animals that underwent surgery and ligation of the sciatic nerve, when the tumors reach large sizes, exceeding this indicator in the control group, needs to be clarified.

In vivo tumor models created in various mouse strains play an important role in studies on antitumor therapies. An adequately selected model allows one to sufficiently assess the significance of the effect of the studied substance on molecular targets, its effect on the growth and viability of the tumor, and also to reveal a therapeutic window between the effectiveness of treatment and toxicity. An appropriately selected model allows an adequate assessment of the significance of the effect of the studied substance on molecular targets, the model’s effect on the growth and viability of the tumor, and also detection of a therapeutic window between the treatment effectiveness and toxicity. Xenografts of human tumors transplanted to immunodeficient mice are one of the most popular models for studying tumorigenesis and antitumor effects. Immunodeficiency of animal recipients is the prerequisite to prevent the rejection of tumor material from another biological species. A large number of different mouse strains have been developed, with varying severity of immune system defects and with various phenotypic and genotypic characteristics. The choice of an animal strain for a model creation depends on the research tasks. The success of an experiment directly depends on choosing the correct strain of experimental animals.

Background: Orthotopic patient-derived xenografts (PDX) in immunodeficient mice are recognized as the most adequate neoplastic model due to their ability to maintain primary tumor properties after implantation. They can be used to study anti-neoplastic effects of pharmacological substances in vivo and to investigate characteristics and mechanisms of carcinogenesis. Results of preclinical studies of pharmacological substances obtained with PDX models are virtually no different from those of subsequent clinical trials. Aim: To develop an orthotopic PDX model of a highly differentiated human pancreatic neuroendocrine tumor (pNET) by implanting a fragment of the patient's tumor into the pancreas of immunodeficient mice. Materials and methods: A tumor fragment was obtained from a patient with a highly differentiated pNET G2 and liver metastasis. Fifteen (15) male immunodeficient Balb/c Nude mice with a mass of 22-24 grams were used to establish the orthotopic PDX model of human well-differentiated pNET. A fragment of primary pNET was orthotopically transplanted into the pancreas of 10 animals. A fragment of the metastatic lesion was transplanted into the liver of 5 animals. The animals were followed for up to 45 days. In vivo monitoring of the tumor growth was performed with a magnetic resonance imaging (MRI) system (ClinScan, Bruker BioSpin, Rheinstetten, Germany). At the end of the experiment, animals were euthanized and autopsies were performed, with routine histopathological examination and immunohistochemical study with antibodies to human chromogranin A, synaptophysin, and the marker of proliferative activity (Ki-67) of both original donor tumor and orthotopic pancreatic and liver xenografts. Results: Obvious changes in the mice condition were noticed at 30 days after surgery. They manifested as an increase in abdominal distension, swelling, and cyanosis in the projection of the pancreas. MRI showed a homogeneous neoplasm in the pancreas. At autopsy, the engraftment rate was 73% of all study animals, with yellow masses with even contours and a volume of about 100 cm3 present within the yellow-pink pancreatic tissues. The morphological assessment showed histological similarity between the original patient's tumor and patient-derived xenografts, which were identified as highly differentiated G2 pNETs. At immunohistochemical assessment, the patient's primary and metastatic tumor tissue specimens expressed anti-chromogranin A (full-blown cytoplasmic reaction) and anti-synaptophysin (mild cytoplasmic reaction) antibodies. Ki-67 was positive in 5.2% of the cells. An immunohistochemical study of the orthotopic tumor fragments and heterotopic tumor fragments showed moderate cytoplasmic staining with antibodies to chromogranin A and synaptophysin. The rate of Ki-67 in the orthotopic pNET model and metastatic model does not exceed 5% and 8%, respectively. Conclusion: Engraftment of tumor material after transplantation of human pancreatic cancer was observed in 73% of the cases, which should be considered a good first passage implantation result. The morphological studies confirmed that the orthotopic PDX was a well-differentiated pNET, histologically corresponding to the donor tumor. The model created in the experiment mirrors the histological characteristics of the donor tumor and can be used in preclinical studies of new treatments for well-differentiated pNETs, including those of antitumor activity of new pharmacological substances.

Introduction. To study the antitumor effect of substances in vivo, it is necessary to create a model that reflects the main characteristics of a human disease. Patient-like xenografts (Patient Derived Xenograft, PDX) on immunodeficient mice can meet this requirement. Patient-like tumor models are considered the most progressive because of their ability to maintain their initial properties, characterized by diversity at the histological and molecular level, after implantation. The aim of the study was to create a PDX model of human esophageal cancer in the cervical esophagus of immunodeficient mice.Material and Methods. To create a PDX-model of human esophageal cancer, 11 male Balb/c Nude immunodeficient mice weighing 19-22 g were used. A tumor fragment was taken from a patient with a diagnosis of ulcerative cancer - a moderately differentiated squamous cell carcinoma without keratinization.Results. As a result of implantation of a donor tumor fragment, complete engraftment of the material was observed in 6 (54.5 %) out of 11 animals, which is consistent with published data. according with the results of morphological studies, a patient-like xenograft is a squamous cell carcinoma, which histologically corresponds to the patient's tumor.

This article reviews modern ideas about the pathogenesis of chronic pain in cancer patients and describes main approaches to its relief. Special attention is focused on factors important for the development of a patient-specific approach to the pathophysiology and management of chronic pain syndrome. These factors include genetics, gender, age, early anamnesis, patients’ immunological and endocrine status, as well as those shedding light on the pathogenetic aspects of chronic pain thus facilitating the choice of an optimal therapeutic approach. The review identifies limitations of pharmacotherapy as the major method of chronic pain management and justifies the need for alternative approaches. The latter include monitoring of the circadian rhythms of pain and various nonspecific effects, such as physical factors, psychological methods or reflex therapy. The experience and possibilities of non–pharmacological methods in the complex pathogenetic therapy of chronic pain are analysed, along with preventive measures permitting the development of chronic pain to be avoided. The pathological disorganizing and stressful role of chronic pain is considered with regard to the theory of functional systems. The pathogenetic significance of chronic pain in carcinogenesis and cancer progression is illustrated by examples from scientific literature. The authors emphasize the necessity of effective pain prevention, including invasive methods, in order to ensure an acceptable quality of life for cancer patients at any stage of the malignant process.