Anti-Cancer Potential of Transiently Transfected HER2-Specific Human Mixed CAR-T and NK Cell Populations in Experimental Models: Initial Studies on Fucosylated Chondroitin Sulfate Usage for Safer Treatment.

Human epidermal growth factor receptor 2 (HER2) is overexpressed in numerous cancer cell types. Therapeutic antibodies and chimeric antigen receptors (CARs) against HER2 were developed to treat human tumors. The major limitation of anti-HER2 CAR-T lymphocyte therapy is attributable to the low HER2 expression in a wide range of normal tissues.

Cure of Mice with Advanced Ovarian Adenocarcinoma CaO1 by the Serum Blood Proteins.

After removal of the primary tumor node, tumor-specific activity appears in the serum that blocks tumor growth in mice. This activity is observed at the time interval when activity of the tumor growth-stimulating factor is not determined. Administration of blood serum (0.

Chondroitin Sulfate and Fucosylated Chondroitin Sulfate as Stimulators of Hematopoiesis in Cyclophosphamide-Induced Mice.

The immunosuppression and inhibition of hematopoiesis are considered to be reasons for the development of complications after intensive chemotherapy and allogeneic hematopoietic stem cell transplantation. Chondroitin sulfate (), isolated from the fish , and fucosylated chondroitin sulfate (), isolated from the sea cucumber , were studied for their roles as stimulators of hematopoiesis in a model of cyclophosphamide-induced immunosuppression in mice. The recombinant protein r G-CSF was applied as a reference.

Combination of Muramylpeptides from Gram-Negative Bacteria Corrects Cyclophosphamide-Induced Disorders of Hematopoiesis and Spleen Cell Composition in Mice with B16 Melanoma.

We studied the effect of a combination of three muramylpeptides from gram-negative bacteria (Polymuramyl) on hematological parameters, morphology of the spleen, and serum cytokine level in mice with B16 melanoma treated with cyclophosphamide. Intraperitoneal administration of cyclophosphamide to tumor-bearing animals sharply reduced the number of leukocytes, especially neutrophils, in the blood and depleted the cellular composition of the spleen white pulp. Subsequent three daily intramuscular injections of Polymuramyl in doses of 70 and 860 ng/mouse for 3 days, as well as subcutaneous injection of the reference drug filgrastim (granulocytic CSF) in a dose of 12 μg/mouse partially corrected hematopoietic disorders and restored the cellular composition of the spleen.

Effect of Cathepsine L1 on Transformation of Malignant Melanoma B16 Cells into Melanocytes.

We studied the effects of cathepsins produced by immunocompetent cells of intact mice, mice with B16 melanoma, mice with removed B16 melanoma, and mice with removed Ehrlich carcinoma on the growth of B16 melanoma. Incubation of B16 melanoma cells with cathepsins from immunocompetent cells of intact mice, mice with B16 melanoma, and mice with removed Ehrlich carcinoma did not affect tumor growth. Incubation of B16 melanoma cells with cathepsin from immunocompetent cells of mice with removed B16 melanoma was followed by complete loss of malignancy by these cells.

A Combination of Muramylpeptides from Gram-Negative Bacteria Corrects Hematological and Immunological Disorders Induced by Cyclophosphamide.

We have studied the effect of a combination of three natural muramylpeptides containing a meso-diaminopimelic acid residue (polyramyl) on the subpopulations of circulating T cells, spleen morphology, and leukocyte level in the blood of C57Bl/6 mice with cyclophosphamideinduced immunosuppression. Intraperitoneal injections of cyclophosphamide in a dose of 100 mg/kg on days 1, 3, 5, and 7 of the experiment reduced leukocyte count and the relative number of CD4 T cells in the blood, and also depleted the cellular composition of splenic white pulp on day 10. Subcutaneous injections of polyramyl in a dose of 200 μg/mouse on days 8 and 9 practically completely restored blood leukocytes count and morphology of the splenic white pulp.

Influence of Modified Fucoidan and Related Sulfated Oligosaccharides on Hematopoiesis in Cyclophosphamide-Induced Mice.

Immunosuppression derived after cytostatics application in cancer chemotherapy is considered as an adverse side effect that leads to deterioration of quality of life and risk of infectious diseases. A linear sulfated (1→3)-α-l-fucan prepared by chemical modification of a fucoidan isolated from the brown seaweed , along with two structurally related synthetic sulfated oligosaccharides, were studied as stimulators of hematopoiesis on a model of cyclophosphamide immunosuppression in mice. Recombinant granulocyte colony-stimulating factor (), which is currently applied in medicine to treat low blood neutrophils, was used as a reference.

Fucoidan and Fucosylated Chondroitin Sulfate Stimulate Hematopoiesis in Cyclophosphamide-Induced Mice.

Application of cytostatics in cancer patients' chemotherapy results in a number of side effects, including the inhibition of various parts of hematopoiesis. Two sulfated polysaccharides, fucoidan from the seaweed () and fucosylated chondroitin sulfate from the sea cucumber (), were studied as stimulators of hematopoiesis after cyclophosphamide immunosuppression in mice. Recombinant granulocyte colony-stimulating factor () was applied as a reference.

Biopiracy of natural products and good bioprospecting practice.

Background: Biopiracy mainly focuses on the use of biological resources and/or knowledge of indigenous tribes or communities without allowing them to share the revenues generated out of economic exploitation or other non-monetary incentives associated with the resource/knowledge.

Methods: Based on collaborations of scientists from five continents, we have created a communication platform to discuss not only scientific topics, but also more general issues with social relevance. This platform was termed 'PhytCancer -Phytotherapy to Fight Cancer' (www.

Influence of fucoidans and their derivatives on antitumor and phagocytic activity of human blood leucocytes.

The immunotropic activity of structurally different fucoidans and their derivatives towards isolated immune blood cells, effectors of innate immune system, was studied. The most potent effect was observed for high molecular weight fucoidan CF from the alga Chordaria flagelliformis, whose backbone is built of (1→3)-linked units of α-L-fucopyranose, and branches included residues of α-D-glucuronic acid and α-L-fucofuranose. This compound at the concentration of 0.

Conformational changes in inter-α-trypsin inhibitor heavy chain 4 activate its tumor-specific activity in mice with B16 melanoma.

It is known that blood serum proteins of tumor‑bearing mice display tumor‑specific activity. However, to date, the nature of this activity has remained elusive, and no tumor‑specific proteins have been detected in the blood serum of tumor‑bearing animals compared with those in healthy animals. The present study postulated and investigated the hypothesis that the observed tumor‑specific activity of the blood serum proteins is not associated with the appearance of novel serum proteins but with changes in the conformation of the existing ones.

Changes in the serum protein composition in mice with transplanted Ehrlich's carcinoma.

Injection of blood serum from mice with Ehrlich's carcinoma stimulates the growth of transplanted tumor, which proves the presence of tumor-specific factors in the serum. Experiments on (CBA×C57Bl/6)F1 male mice with transplanted Ehrlich's carcinoma demonstrated the appearance of new proteins in the serum, some of them are identified. The authors suggest continuing the search for tumor-associated factor by combining proteomic analytical methods and testing of identified candidate proteins for their effects on tumor growth.

Experimental evaluation of combined immunotherapy for tumors.

The minimal vaccination dose of tumor cells was determined on experimental models. The effectiveness of antitumor immunotherapy with activated natural killer cells or dendritic cell vaccine (monotherapy or combined treatment) was evaluated in vivo. The inhibition of tumor growth was more pronounced after combination therapy with activated natural killer cells and dendritic cell-based vaccine.

Tumor-specific blood serum factors as determinants of tumor growth.

In the present review, we focus on the importance of blood serum factors for tumor growth in vivo. Data from mice experiments indicate the existence of serum factors, which increase the mitotic index of Ehrlich carcinoma cells from 15 to 80%. The impaired production of these factors increases the life span of tumor-bearing animals from 14-20 days to 90 days.

[Analysis of extracellular proteome of Staphylococcus aureus 6 at the end of exponential growth phase].

Aim: Determine protein specter that Staphylococcus aureus synthesizes and secretes at early growth phase--the exponential phase.

Materials And Methods: Proteins secreted by S. aureus strain 6 into cultivation medium at the end of exponential growth phase (4.

Growth-dependent release of carbohydrate metabolism-related and antioxidant enzymes from Staphylococcus aureus strain 6 as determined by proteomic analysis.

Proteins released into the culture medium by Staphylococcus aureus (S. aureus) strain 6 were determined at the end of the exponential growth phase (4.5 h).

Identification of serpin (alpha-1-antitrypsin) as serum growth inhibitory factor in murine ehrlich carcinoma by proteomics.

It is well established that serum factors play a role in relapse of tumor diseases after removal of the primary tumor. The molecular nature of these factors and their mechanism of action remain unknown. We focused on host-related mechanisms to identify tumor-specific serum factors of mice bearing Ehrlich carcinoma, which have the potential to confer resistance towards tumor development.

Mononuclear leukocytes from mice with resected tumor induce resistance to transplantation of tumor cells to animals.

Experiments on male C57Bl/6 mice with intraperitoneally transplanted Ehrlich carcinoma and DBA/2 mice with subcutaneously transplanted S-91 melanoma showed that preliminary injection of mononuclear leukocytes obtained from animals 6-8 h after tumor resection induce resistance to transplantation of malignant transformed cells. Our results suggest that not only humoral factors, but also immunocompetent cells are involved in the regulation of tumor growth. The resistance to tumor transplantation was not induced by mononuclear leukocytes isolated over the first hours and 10-12 h after removal of the primary tumor node, which excludes the direct cytotoxic effect of these cells and suggests that this phenomenon is not associated with activation of the effector mechanisms for innate and adoptive immunity.

Evaluation of immunotherapy efficiency in mouse CaO-1 ovarian carcinoma treated by vaccines based on dendritic cells.

Injection of dendritic cells, pulsated by tumor lysate or mucin, containing CA 125 antigen, led to a more than 50% inhibition of tumor growth in female CBA mice with transplanted mouse pseudomucinous CaO-1 ovarian carcinoma in comparison with the control. Tumor-associated CA 125 antigen can be used for obtaining dendritic cell vaccines against ovarian malignant tumors. This trend will extend the potentialities of application of antitumor vaccines based on dendritic cells, as clinical use of this technology is limited by the need in patient's tumor material.

Induction of resistance to murine tumor development is associated with alterations in the glycosylation of blood serum proteins.

The phenomenon of accelerated metastatic tumor growth following the removal of the primary tumor is a major reason for cancer relapse, caused by underlying mechanisms that are not as yet understood. We hypothesized that a growth-stimulating factor is produced by the tumor-bearing host. This assumption was confirmed by an experiment involving the removal of a primary tumor (ascitic and solid Ehrlich carcinoma cells) from C57B1/6 mice, after which accelerated proliferation was observed in the remaining tumor cells.

[Correction of cytostatic-induced immunosupression with staphylococcal vaccine in mice].

Studies aimed on evaluation of possibility for correction of cyclophosphan-induced immunosuppression in BALB/c mice by using acellular staphylococcal vaccine "Staphylovac" (SV). Cyclophosphan (CP) administered to mice four times with 24 hours intervals decreased levels of T-, B-, T-regulatory (T-reg CD4/CD25/Foxp3) lymphocytes, increased quantity of cells expressing early activation marker CD25 (assessment after 4 hours). Administration of SV along side with cytostatic does not influenced significantly on characteristics of CP-induced immunosuppression at the moment of its assessment.

[Protective activity of secreted proteins of Streptococcus pneumoniae and Klebsiella pneumoniae].

Protective efficacy of secreted proteins of Streptococcus pneumoniae and Klebsiella pneumoniae cultivated on cardiocerebral broth and semisynthetic growth medium respectively was studied in vivo. Fraction with molecular weight 30 - 50 kDa obtained by the method of membrane fractionation had high protective efficacy. Two-dose immunization of mice with this fraction provided 80 - 100% protection from infection by homologous strains of S.

Hemoglobin-associated proteins isolated from blood serum of Ehrlich carcinoma-bearing mice.

In the present study, we analyzed differential composition of blood serum from Ehrlich carcinoma-bearing and healthy male C57Bl/6 mice by isolating complexes of hemoglobin and other serum proteins by a proteomic approach (gel filtration, gel electrophoresis, and mass spectrometry). The hemoglobin fractions isolated from the serum of mice- bearing tumors contained several proteins with molecular weights of 15, 65, 68, and 100 kDa, while hemoglobin fractions isolated from the serum of healthy mice did not contain additional protein bands. These bands were identified by MALDI-TOF as haptoglobin, serum albumin, a homologue of alpha-fetoprotein, and hemoglobin-alpha.

Specificity of relapses and metastases of experimental transplanted Ehrlich carcinoma and B16 melanoma.

Experiments on female (CBAxC57Bl/6)F1 mice with simultaneously transplanted Ehrlich carcinoma and B16 melanoma showed that removal of one of the primary nodes led to metastasizing of the removed tumor alone. It seems that this specificity of the inhibitory effect of the primary tumor can be explained by peculiarities of glycosylation and subsequent complex formation of serum proteins with the tumor.

[Comparative characteristic of the methods of immunocytochemistry and immunomagnetic separation for detection of cytokeratin-positive cells in bone marrow and lymph nodes].

Comparative study of cytokeratin-positive (CK+) cells, isolated from bone marrow and lymph node micrometastases in patients with lung and esophageal cancer, was performed using the methods of immunocytochemistry and immunomagnetic separation. It was found that immunocytochemical analysis permitted the detection of CK+ cells in the smears of bone marrow of oncologic patients. All the samples of bone marrow with immunocytochemically demonstrated CK+ cells, contained also the cellular complexes marked by magnetic spheres.