Characteristics of the Antitumor Effect of Doxorubicin and Pegylated Hyaluronidase on Models of Rat Brain Tumors.

Hyaluronidase increases tissue permeability and diffusion of the extracellular fluid by cleaving hyaluronan, the primary component of the extracellular matrix. Hyaluronidase pegylation (Hyal-PEG) decreases its clearance and enhances biodistribution. The pro- and anticancer activity of Hyal-PEG and a combination of Hyal-PEG with doxorubicin were studied in vitro (morphological analysis of rat glioblastoma 101.8 spheroids) and in vivo (by the survival time of rats after intracerebral transplantation of the tumor and morphological analysis). In the presence of doxorubicin and Hyal-PEG in the culture medium in vitro, spheroids lost their ability to adhere to the substrate and disintegrate into individual cells. Intracerebral transplantation of the tumor tissue with Hyal-PEG did not accelerate glioblastoma growth. The mean survival time for animals receiving transplantation of the tumor alone and in combination with Hyal-PEG was 13 and 20 days, respectively. In one rat with transplanted tumor and Hyal-PEG, this parameter increased by 53%. The survival time of rats receiving systemic therapy with doxorubicin and Hyal-PEG significantly increased (p=0.003). Antitumor effect of therapeutic doses of doxorubicin combined with Hyal-PEG was demonstrated on the model of rat glioblastoma 101.8 in vitro. Hyal-PEG inhibited adhesion of tumor cells, but did not cause their death. Transplantation of Hyal-PEG-treated tumor did not reduce animal survival time. Systemic administration of therapeutic doses of doxorubicin with Hyal-PEG increased survival time of rats with glioblastoma 101.8.

Gene Expression Profile of 3D Spheroids in Comparison with 2D Cell Cultures and Tissue Strains of Diffuse High-Grade Gliomas.

The use of relevant, accessible, and easily reproducible preclinical models of diffuse gliomas is a prerequisite for the development of successful therapeutic approaches to their treatment. Here we studied the gene expression profile of 3D spheroids in a comparison with 2D cell cultures and tissue strains of diffuse high-grade gliomas. Using real time PCR, we evaluated the expression of Gfap, Cd44, Pten, S100b, Vegfa, Hif1a, Sox2, Melk, Gdnf, and Mgmt genes playing an important role in the progression of gliomas and regulating tumor cell proliferation, adhesion, invasion, plasticity, apoptosis, DNA repair, and recruitment of tumor-associated cells. Gene expression analysis showed that 3D spheroids are more similar to tumor tissue strains by the expression levels of Gfap, Cd44, and Pten, while the expression levels of Hif1a and Sox2 in 3D spheroids did not differ from those of 2D cell cultures, the expression levels S100b and Vegfa in 3D spheroids was higher than in other models, and the expression levels of Melk, Gdnf, and Mgmt genes changed diversely. Thus, 3D spheroid model more closely mimics the tumor tissue than 2D cell culture, but still is not the most relevant, probably due to too small size of spheroids, which does not allow reproducing hypoxia and apoptotic and necrotic processes in the tumor tissue.

Differential Markers of Subpopulations of Epithelial Cells of the Larynx in Squamous Cell Carcinoma.

In squamous cell carcinoma of the larynx, the population of epithelial cells in the tumor tissue is initially heterogeneous and, in addition to tumor cells invading the organ mucosa, includes normal epithelial cells of protein-mucous glands and cells of the stratified epithelium covering the mucous membrane. A search for differential markers to separate these subpopulations was carried out. The surface marker CD44 and cytokeratins 5 and 17 that are often used to verify carcinoma cells, are common markers for all epithelial cells of the larynx. In highly differentiated carcinoma, subpopulations of normal and tumor epithelial cells can be separated by the level of expression of cytokeratins 10 and 18 and nuclear markers Ki-67 and p63. However, in moderately differentiated carcinoma, tumor cells and normal cells of the basal layer of the stratified epithelium covering the mucous membrane of the larynx have similar phenotypes, which should be taken into account when conducting experimental studies.

Calculation of the Biological Efficiency of the Proton Component from 14.8 MeV Neutron Irradiation in Computational Biology with Help of Video Cards.

Fast neutron therapy, which previously has demonstrated effective results, but along with a large number of complications, can again be considered a promising treatment method in the treatment of cancer. One of the ways of analyzing the relative biological efficiency and accurate biological dose of fast neutrons in body tissues is to improve the algorithms of computational biology and mathematical modeling. A high-performance computing code was written which allows to estimate in real-time mode the biological dose of the proton component from the action of neutron radiation with an energy of 14.8 MeV. A comparative analysis of the computing performance on various video cards was also performed.

Influence of Sucrose on the Efficiency of Cryopreservation of Human Umbilical Cord-Derived Multipotent Stromal Cells with the Use of Various Penetrating Cryoprotectants.

We studied the influence of sucrose applied in combination with different concentrations of penetrating cryoprotectants (DMSO, ethylene glycol, and glycerol) on the efficiency of cryopreservation of umbilical cord-derived multipotent stromal cells (MSC). The results indicate that these cells can be cryopreserved with the use of 5-10% DMSO or ethylene glycol with equal efficiency; addition of 0.2 M sucrose does not affect cell survival after thawing. The efficiency of glycerol as a cryoprotectant increases with increasing its concentration from 5 to 10%, but remains significantly lower than the efficiency of DMSO or ethylene glycol. Addition of sucrose to a final concentration of 0.2 M increases the efficiency of glycerol. The efficiency of combination of 10% glycerol and sucrose was comparable with that of combinations of DMSO and ethylene glycol with sucrose. The mechanism of the observed enhancement is apparently related to the influence of sucrose on the dynamic properties of the lipid membranes and facilitation of glycerol diffusion into the cells.

Quantitative and Qualitative Characterization of Phagocytic Activity of Macrophages of Bone Marrow and Fetal Origin.

We compared phagocytic activity of macrophages of monocyte origin and Kupffer cells under the influence of M1 and M2 inducers and without activation. Cultures of monocyte-derived macrophages and Kupffer cells were characterized by intensive expression of CD68 that was not affected by activation factors. At the same time, these cultures demonstrated different dynamics of phagocytic activity. Monocyte-derived macrophages initially had more pronounced absorption capacity that gradually increased during the experiment. Kupffer cells were characterized by abrupt fluctuations of phagocytic activity: sharp growth and rapid saturation. Despite these differences, the endosomes produced by monocyte-derived macrophages and Kupffer cells had similar degrees of maturity.

DMSO-Free Cryopreservation of Human Umbilical Cord Tissue.

Human umbilical cord represents a source of multipotent stromal cells of a supreme therapeutic potential. The cells can be isolated from either fresh or cryopreserved umbilical cord tissues. DMSO is a cryoprotectant most commonly used for preservation of umbilical cord tissues; however, cyto- and genotoxicity of this compound is evident and well documented. In the present study we performed successful cryopreservation of the umbilical cord tissue using other cryoprotectants: propylene glycol, ethylene glycol, and glycerol. Of these, 1.5 M ethylene glycol and 20% glycerol turned out to be the best in terms of the preservation of living cells within the frozen tissue, early onset of migration of these cells out of the thawed explants, and overall efficacy of multipotent stromal cell isolation. Cryobanking of tissues can improve availability of multiple cell products for medical purposes and promote the development of personalized medicine.

Dynamics of Expression of Cytokine Genes and Macrophage Content in the Lungs and Kidneys after Subtotal Hepatectomy in Rats.

The role of the lungs and kidneys in liver regeneration after subtotal hepatectomy was studied on a rat model. It was found that production of hepatocyte growth factor (HGF) in the lungs and kidneys and expression of cytokine genes Il1b, Il6, Il10, and tnfa significantly increased. Analysis of the dynamics of lung macrophage population showed that accumulation of HGF and the increase in the expression of cytokine genes in the lungs were accompanied by simultaneous increase in the number of CD68+ cells, which attested to the leading role of macrophages in activation of HGF synthesis in the lungs. Macrophage content in the kidneys after subtotal hepatectomy did not increase.

Expression of Cytokine Genes and Growth Factors in Rat Lungs and Kidneys after Subtotal Hepatectomy.

Expression of il1b, il6, il10, tnfa, hgf, tgfb, vegf, and fgf2 genes in the lungs and kidneys was examined on rat model of liver regeneration after subtotal hepatectomy. Enhanced expression of il6, il10, tnfa, hgf, and fgf2 genes was detected at the early terms after 80% liver resection.

Angiogenic Potential of Multipotent Stromal Cells from the Umbilical Cord: an In Vitro Study.

The mechanisms of proangiogenic activity of multipotent stromal cells from human umbilical cord were analyzed in vitro. The absence of secreted forms of proangiogenic growth factor VEGF-A in the culture medium conditioned by umbilical cord-derived multipotent stromal cells was shown by ELISA. However, the possibility of paracrine stimulation of cell proliferation, mobility, and directed migration of endothelial EA.hy926 cells was demonstrated by using MTT test, Transwell system, and monolayer wound modeling. The capacity of multipotent stromal cells to acquire the phenotype of endothelium-like cells was analyzed using differentiation media of three types. It was found that VEGF-A is an essential but not sufficient inductor of differentiation of umbilical cord-derived multipotent stromal cells into CD31+ cells.

Role of Progenitor Cells in Liver Regeneration after Subtotal Resection.

In the liver of rats subjected to subtotal liver resection (80% organ weight), the expression of sox9 gene and SOX9 protein content increased and cells with hepatocyte morphology expressing SOX9 appeared; the proportion of cells expressing cytokeratin-19 also increased. Based on these data, we cannot completely exclude the involvement of resident progenitor cells and hepatocyte reprogramming in liver regeneration after subtotal resection, however, the contribution of these processes seems to be insignificant. The leading mechanism of liver mass recovery after subtotal resection is proliferation of hepatocytes.

Effect of Endothelial Cells on Angiogenic Properties of Multipotent Stromal Cells from the Umbilical Cord during Angiogenesis Modeling in the Basement Membrane Matrix.

Short-term cell culturing on basement membrane matrix is a common and very convenient in vitro model of angiogenesis. We studied the possibility of interaction of multipotent stromal cells from the umbilical cord and Ea.hy926 endothelial cells on this model at the early and late periods of the experiment. Multipotent stromal cells alone and in combination with endothelial cells formed an unstable tubular network. Clusters formed after its disassembling later became the sprouting centers in co-culture of the two cell types, but not in pure culture of multipotent stromal cells. Multipotent stromal cells with CD31+ phenotype constitute the structural basis of newly formed stable 3D capillary-like network. Prolongation of the time of culturing and combination of the two in vitro models of angiogenesis (tubulogenesis and sprouting) allowed more complete assessment of the angiogenic potential of multipotent stromal cells.

Effect of multipotent stromal cells on the function of cell mitochondria in regenerating liver.

Intrasplenic allogeneic transplantation of multipotent stromal cells from the umbilical cord stimulates hepatocyte proliferation and promotes recovery of liver weight in rats after subtotal resection (80% organ weight). It can be hypothesized that this effect of multipotent stromal cells is due to more rapid recovery of the number of mitochondria and normalization of mitochondrial function of liver hepatocytes.

Hemopoietic cell proliferation and death in the regenerating fetal rat liver.

The proliferation and death of hemopoietic cells in the regenerating liver of 17-day outbred albino rat fetuses were studied during 2 days after resection of 20% of the organ. The mitotic index of hemopoietic cells in the resected liver increased significantly 24 h after the operation in comparison with the control fetuses. No increase in the counts of apoptotic hemopoietic cells was detected in the regenerating liver. Hence, resection of 20% of the liver in rat fetuses stimulated the proliferation of hemopoietic cells and did not stimulate their apoptosis.

Tissue engineering construct on the basis of multipotent stromal adipose tissue cells and Osteomatrix for regeneration of the bone tissue.

We developed a new method of creation of tissue engineering constructs for regeneration of the bone tissue based on the principle of free distribution of cells in a fibrin clot within a scaffold. The tissue engineering construct includes multipotent stromal adipose tissue cells committed in osteogenic lineage, platelet-rich plasma, and resorbed material on the basis of xenogeneic bone collagen. The culture of bone progenitor cells was characterized by the main markers of osteoblastic differon. The material meets all requirements for materials intended for tissue engineering. An innovative high-technological tissue engineering product for clinical application is prepared.

Angiogenesis after transplantation of auto- and allogenic cells.

Neoangiogenesis after transplantation of auto- and allogenic mononuclears and multipotent stromal cells from the bone marrow was studied on the model of inflammatory angiogenesis. Transplanted auto- and allogenic cells stimulate the formation of new blood vessels in the granulation tissue, this manifesting in an increase in the quantity and volume density of blood vessels. The most pronounced angiogenesis was observed after transplantation of allogenic mononuclears and multipotent stromal cells. It was associated with intense inflammatory infiltration, with less numerous and mature collagen fibers in the granulation tissue. Injection of allogenic cells led to stimulation and chronization of inflammation, infiltration with inflammatory and poorly differentiated cells, and more pronounced and lasting angiogenesis. However, neither auto-, nor allogenic transplanted labeled cells were detected in the walls of new blood vessels. Hence, it seems that bone marrow mononuclears and multipotent stromal cells stimulated angiogenesis mainly at the expense of production of angiogenic factors, and after transplantation of allogenic cells also by stimulating the inflammation.

Regeneration of skull bones in adult rabbits after implantation of commercial osteoinductive materials and transplantation of a tissue-engineering construct.

We performed a comparative study of reparative osteogenesis in rabbits with experimental critical defects of the parietal bones after implantation of commercial osteoinductive materials "Biomatrix", "Osteomatrix", "BioOss" in combination with platelet-rich plasma and transplantation of a tissue-engineering construct on the basis of autogenic multipotent stromal cells from the adipose tissue predifferentiated in osteogenic direction. It was found that experimental reparative osteogenesis is insufficiently stimulated by implantation materials and full-thickness trepanation holes were not completely closed. After transplantation of the studied tissue-engineering construct, the defect was filled with full-length bone regenerate (in the center of the regenerate and from the maternal bone) in contrast to control and reference groups, where the bone tissue was formed only on the side of the maternal bone. On day 120 after transplantation of the tissue-engineering construct, the percent of newly-formed bone tissue in the regenerate was 24% (the total percent of bone tissue in the regenerate was 39%), which attested to active incomplete regenerative process in contrast to control and reference groups. Thus, the study demonstrated effective regeneration of the critical defects of the parietal bones in rabbits 120 days after transplantation of the tissue-engineering construct in contrast to commercial osteoplastic materials for directed bone regeneration.

Effect of dexamethasone on differentiation of multipotent stromal cells from human adipose tissue.

Effect of dexamethasone on differentiation of multipotent stromal cells from human adipose tissue was evaluated. Addition of dexamethasone to growth medium resulted in active adipogenesis. Addition of dexamethasone to the osteogenic medium (containing active vitamin D3 form as the main inductor) led to simultaneous realization of the adipogenic and osteogenic potencies of multipotent stromal cells of the adipose tissue. Hence, the quality of the transplant on the basis of predifferentiated multipotent stromal cells from the adipose tissue for bone tissue repair can be deteriorated by dexamethasone directing some cells to adipogenic development.

Morphological changes in paraurethral area after introduction of tissue engineering construct on the basis of adipose tissue stromal cells.

We studied morphological changes in the paraurethral area of Wistar rats after introduction of tissue engineering constructs on the basis of multipotent mesenchymal stem cells and gelatin sponge. The tissue engineering construct containing autologous culture of the stromal fraction of the adipose tissue was most effective. After introduction of this construct we observed more rapid degradation of the construct matrix and more intensive formation of collagen fibers.

Directions of migration of bone marrow mononuclears after intracoronary transventricular injection.

Directions of migration of mononuclear bone marrow cells after intracoronary transventricular injection procedure developed by us were experimentally studied. After nonselective injection of cells into the right and left coronary arteries in rats, the labeled cells were detected only in the damaged zone of the myocardium. Localization of transplanted mononuclears in the scar attests to their homing into the damaged zone. Numerous cells were found in the red pulp of the spleen and solitary cells were detected in the liver and lungs. In the heart, the labeled transplanted cells were detected only in the scar zone at all terms of the study; they were not incorporated into the vascular walls, but were surrounded by thick bundles of collagen fibers and probably underwent differentiation into fibroblasts. No data on possible differentiation of the transplanted cells into vascular cells or cardiomyocytes were obtained.