Immunophenotypic characteristics and karyotype analysis of bone marrow-derived mesenchymal stem cells of rabbits during in vitro cultivation

The aim of this study was to establish the immunophenotypic profile and karyotypic stability of bone marrow mesenchymal stem cells (MSCs) of rabbits at the early passages in vitro following the application of different methods of dissociation of cellular material. MSCs were obtained from the femur bone marrow of three clinically healthy rabbits under general anaesthesia. Bone marrow aspirate was seeded in Petri dishes and cultured in a CO2 incubator with 5% CO2 at 37.0oC using a standard procedure. Immunohistochemical detection of nuclear proteins, cytoskeletal proteins and cell adhesion were performed by immunohistochemical analysis and karyotype analysis of MSCs following the enzyme and chelating methods of dissociation of the cell monolayer. The results of the immunophenotypic analysis of rabbit bone marrow MSCs showed that at the first, seventh, twelfth, and eighteenth passages these cells express markers of mesenchymal, muscle, epithelial and nerve cells. The choice of the enzyme or chelating method of dissociation of a culture of rabbit mesenchymal stem cells affects their cytogenetic variability. Dissociation of the MSCs monolayer with ethylenediaminetetraacetic acid produces a cell culture with fewer quantitative and qualitative changes in the chromosome apparatus as compared to the enzyme method. Rabbit MSCs express markers of mesenchymal (vimentin, actin), muscle, epithelial and nerve (E-cadherin, N-cadherin) cells that are essential for differentiation of these cells. The chelating method of dissociation of a culture of rabbit mesenchymal stem cells, using ethylenediaminetetraacetic acid during cultivation, is more advantageous than the enzyme method of dissociation because it leads to less cytogenetic variability.

THE INFLUENCE OF BIFIDOBACTERIUM ANIMALIS AND LECTIN OF B. SUBTILIS IMV B-7724 ON THE ANTITUMOR IMMUNE RESPONSE OF MICE WITH EHRLICH ADENOCARCINOMA

AIM

To investigate the effect of bacteria of the genus Bifidobacterium and the extracellular metabolite of B. subtilis IMV B-7724 on the antitumor immune response of mice with a model tumor.

MATERIALS AND METHODS

The study was conducted on Balb/c mice with transplanted solid Ehrlich adenocarcinoma (ACE). Starting from the 2nd day after the transplantation of tumor cells, the animals of the experimental groups were treated with lectin of B. subtilis IMV B-7724 (s/c, 1 mg/kg of weight), Bifidobacterium animalis (per os, 7 × 105 CFU/mouse) or their combination. The immunological studies were performed on the 21st and 28th days of tumor growth. The functional activity of natural killer cells (NK), cytotoxic T-lymphocytes (CTL), as well as the ability of lymphocytes from the peripheral lymph nodes (PLN) to transform into blast cells under the influence of T- (Con A) and B-cell (LPS) mitogens were determined.

RESULTS

Administration of probiotic components to the mice with ACE led to the activation of innate immune responses, that is, to a significant increase in the cytotoxic activity of NK, especially in the case of their combined use. The NK cytotoxicity index was higher than that in the non-treated ACE-bearing mice and the intact control by 3.7 and 2.1 times, respectively (p < 0.05). Similarly, the highest specific cytotoxic activity of spleen lymphocytes was observed upon the combined use of the microbial preparations: the CTL cytotoxicity index was nearly 2.5-fold higher than in the non-treated ACE-bearing mice. The data on the ability of PLN lymphocytes to transform into blast cells under the influence of Con A and LPS indicated the preservation of the functional activity of lymphocytes in the animals of the experimental groups during ACE growth.

CONCLUSION

Both B. animalis and lectin of B. subtilis IMV B-7724 have a significant influence on the effectors of the natural and adaptive immunity of mice with ACE. Their combined use was found to be the most effective.

Assessment of biosafety and toxicity of hydrophilic gel for implantation in experimental in vitro and in vivo models

BACKGROUND

The assessment of biosafety of pharmacologically active substances is crucial for determining the feasibility of their medical use. There are controversial issues regarding the use of substances of different origins as implants.

METHODS

We have conducted the comprehensive studies to determine the in vivo toxicity and in vitro genotoxicity of new generation of hydrophilic gel for implantation (production name of the substance "Activegel") to detail its characteristics and assess its biosafety.

RESULTS

In vivo studies have shown the absence of clinical manifestations of intoxication in animals and no abnormalities in their physiological condition, general and biochemical blood tests. Evaluation of the site of the gel application showed no inflammatory reaction and evidenced on normal state of tissues of animal skin. The results of the genotoxicity test indicated that the gel did not affect the parameters of DNA comets and the formation of micronuclei, accordingly, had no genotoxic effect on human peripheral blood lymphocytes. When studying the effect of the gel on malignantly transformed cells in vitro, it was found that the gel for implantation did not change the proliferative activity and viability of human breast cancer cells.

CONCLUSIONS

Comprehensive in vitro and in vivo study using various experimental model systems showed that the hydrophilic gel for implantation "Activegel" is non-toxic.

OPTIMIZATION OF EXPERIMENTAL MODEL SYSTEMS FOR EVALUATING RECIPROCAL INFLUENCE OF BIFIDOBACTERIUM ANIMALIS AND HUMAN BREAST CANCER CELLS IN VITRO

BACKGROUND

The development of human breast cancer (BC) is known to be closely related to disturbances in the mammary gland microbiota. Bacteria of the genus Bifidobacterium are an important component of normal breast microbiota and exert antitumor activity. The molecular-biological mechanisms of interaction between BC cells and microbiota members remain poorly studied yet. The aim of this study was to develop and optimize an experimental model system for the co-cultivation of BC cells with Bifidobacterium animalis in vitro.

MATERIALS AND METHODS

Human ВС cells of the MCF-7, T47D, and MDA-MB-231 lines, as well as live and heat-inactivated bacteria of Bifidobacterium animalis subsp. lactis (B. animalis) were used as research objects. The growth kinetics and viability of B. animalis in the presence of different ВС cell lines and without them were determined by both the turbidimetry method and seeding on an elective nutrient medium. Glucose consumption and lactate production by bifidobacteria were assessed by biochemical methods. The viability of BC cells was determined by a standard colorimetric method.

RESULTS

The growth kinetics of B. animalis in the complete DMEM nutrient medium showed standard patterns. The indicators of glucose consumption and lactate production of B. animalis confirm its physiological metabolic activity under the growth conditions. The presence of BC cells in the model system did not affect the duration of the growth phases of the B. animalis cells' population but contributed to the increase in their counts. A significant decrease in the number of live BC cells of all studied lines was observed only after 48 h of co-cultivation with live B. animalis. To achieve similar suppression of the BC cell viability, 10-30-fold higher counts of heatinactivated bacteria were required compared to live ones.

CONCLUSIONS

The optimal conditions for co-cultivation of human BC cells and living B. animalis cells in vitro have been identified.

Evaluation of the duration of new nasal drug interferon α-2b activity in an experimental model system

THIS STUDY AIMED

To develop an adequate system for assessing the duration of IFN antiviral activity in the nasal cavity of animals and to study the antiviral activity of a new IFN drug in the form of a gel in comparison with the known spray form.

METHODS

To assess the duration of the specific activity of IFN, the drugs were administered into the nasal cavity of experimental rats. One, 3, and 4 h after administration, the nasal cavities of the rats were washed out, and the antiviral activity of washed from the nasal cavity (WNC) was analyzed in vitro.

RESULTS

Developed an algorithm to assess the duration of antiviral activity of nasal preparations using a sensitive in vitro test system, in which the analysis of the antiviral activity of WNC made it possible to detect antiviral activity after the administration of nasal forms of IFN-a new variant in the form of a gel in comparison with the IFN spray. It was established that 1 h after the intranasal administration of IFN, the same antiviral activity and IFN concentration is: 266.8 ± 14.0 IU/ml for IFN/spray and 260.2 ± 20.9 IU/ ml for IFN/gel. Three hours after the drugs are administered, their activity decreases but remains at a sufficiently high level: 121.4 ± 5.4 IU/ml for IFN/spray and 88.3 ± 6.2 IU/ml for IFN/gel. Four hours after IFN administration, the concentration of IFN/gel was significantly greater than that of IFN/spray: 39.4 ± 4.9 IU/ml and 10.6 ± 1.0 IU/ml, respectively.

CONCLUSION

The developed system for evaluating the antiviral activity of nasal preparations allows the study of the duration of the local antiviral effect of drugs. The antiviral activity of the IFN nasal preparations persisted for 4 h after their intranasal administration: the concentration of IFN in gel form on the walls of the nasal cavity was significantly greater than that of the IFN spray.

Establishment and characterization of new breast and ovarian cancer cell lines as a model for studying cellular plasticity in vitro

AIM

To compare biological properties of primary tumor cells isolated from malignant effusion of cancer patients with the same cells of permanent lines established during their long-term cultivation in vitro and to assess the impact of phenotypic conversion that was caused by changes in their microenvironment on their behavioral characteristics.

MATERIALS AND METHODS

The study was performed on primary cell cultures from pleural effusion or ascites of breast and ovarian cancer and permanent cell lines derived from them, namely permanent ovarian cancer cell line I, permanent ovarian cancer cell line II and permanent breast cancer cell line I. Biological characteristics were studied using standard cell culture methods and immunocytochemical assays.

RESULTS

Three new cell lines were established from breast and ovarian cancer and cell morphology, migration activity, the kinetics of growth, colony forming activity in semisolid agar and sensitivity to anticancer drug were examined. These characteristics were compared with those of the primary tumor cells. It has been shown that among the primary tumor cells from malignant effusion, cells with mese-nchymal characteristics were the most prevalent. Cultivation of primary cancer cells in vitro leads to a phenotypic change of their population: it becomes more homogeneous in morphology with predominantly epithelial-like cells. Also, later after a number of cell doublings in vitro, the cell population changes to include cells primarily with immunophenotypic properties characteristic of epithelial cells. These changes include increase in number of E-cadherin-positive cells and a decrease in number of vimentin and α- smooth muscle actin-positive cells. It was found that significant changes in expression of epithelial-mesenchymal transition associated proteins in cells during their cultivation in vitro in new microenvironment are accompanied by a rapid change in their sensiti-vity to anticancer drugs.

CONCLUSIONS

The new breast and ovarian cancer cell lines were established and characterized. The induction of phenotypic transdifferentiation in malignant cells from pleural effusion and ascites can be an important approach for suppressing the progression of neoplastic process.