Molecular and Cellular Mechanisms of Antitumor Immune Response Activation by Dendritic Cells.

Dendritic cells (DCs) play a crucial role in the initiation and regulation of the antitumor immune response. Already , DC-based antitumor vaccines have been thoroughly explored both in animal tumor models and in clinical trials. DC-based vaccines are commonly produced from DC progenitors isolated from peripheral blood or bone marrow by culturing in the presence of cytokines, followed by loading the DCs with tumor-specific antigens, such as DNA, RNA, viral vectors, or a tumor cell lysate. However, the efficacy of DC-based vaccines remains low. Undoubtedly, a deeper understanding of the molecular mechanisms by which DCs function would allow us to enhance the antitumor efficacy of DC-based vaccines in clinical applications. This review describes the origin and major subsets of mouse and human DCs, as well as the differences between them. The cellular mechanisms of presentation and cross-presentation of exogenous antigens by DCs to T cells are described. We discuss intracellular antigen processing in DCs, cross-dressing, and the acquisition of the antigen cross-presentation function. A particular section in the review describes the mechanisms of tumor escape from immune surveillance through the suppression of DCs functions.

Design of Polyepitope DNA Vaccine against Breast Carcinoma Cells and Analysis of Its Expression in Dendritic Cells.

Polyepitope DNA vaccine inducing T-cell-mediated immune response against cancer-specific antigens is a promising tool for selective elimination of tumor cells. Breast cancer-specific polyepitope DNA vaccine was designed using TEpredict and PolyCTLDesigner software on the basis of immunogenic peptides of HER2 and Mammaglobin-1 (Mam) tumor antigens. LPS-free preparations of plasmid DNA encoding polyepitope T-cell antigen and full-length copies of HER2 and Mam antigens were obtained. TaqMan-PCR systems for evaluation of the expression of immunogens in cells were created. The protocol of vaccine DNA delivery into dendritic cells was optimized. Expression of the target immunogens in dendritic cells derived from human peripheral blood mononuclear fraction after transfection with plasmid DNA preparations is demonstrated.

[Circulating microRNAs in lung cancer: prospects for diagnostics, prognosis and prediction of antitumor treatment efficiency].

The major methods of microRNA extraction from different biological fluids (particularly, serum and plasma), approaches to the analysis of microRNA concentration and composition, normalization methods used in data analysis are outlined in the review. The advantages and disadvantages of the described methodological approaches are being highlighted. Special attention is given to microRNAs, circulating in blood, which could be used as the markers for minimally invasive lung cancer diagnostics, prediction of antitumor treatment efficiency and disease prognosis. Prospects and limitations arising from the evaluation of clinical significance of microRNAs as the potential tumor markers, and emerging as roles of various microRNAs in the pathogenesis of lung cancer become known, are discussed.

MIRA analysis of RARß2 gene methylation in DNA circulating in the blood in lung cancer.

Analysis of DNA epigenetic mutations in the blood circulating DNA is a prospective trend for creation of noninvasive methods for the diagnosis and treatment efficiency monitoring in cancer. The methylation status of target genes in circulating DNA was evaluated by methods based on preliminary bisulfite conversion of DNA. We used a different approach based on selection of hypermethylated sequences of circulating DNA by means of DNA-methyl-binding protein (methylated CpG island recovery assay, MIRA). Methylation was evaluated for RARß2 tumor suppression gene in circulating DNA in lung cancer and a trend was detected to higher methylation of this gene in the patients in comparison with healthy donors.

Cyclophosphamide metabolite inducing apoptosis in RLS mouse lymphosarcoma cells is a substrate for P-glycoprotein.

RLS lymphosarcoma characterized by enhanced expression of mdr1a and mdr1b genes encoding P-glycoprotein is insensitive to low doses of cyclophosphamide, but is susceptible to its high doses approximating the maximum tolerated doses. Induction of apoptotic death of RLS cells by high doses of cyclophosphamide was demonstrated by cytofluorometry and electrophoresis. Experiments on RLS(40) tumor cells derived from RLS lymphosarcoma and characterized by more intensive expression of mdr1a/1b genes showed that the therapeutic effects of cyclophosphamide increased under conditions of simultaneous suppression of these genes by specific small interfering RNA (siRNA). These findings suggest that active cyclophosphamide metabolite can be a substrate for P-glycoprotein.

[Assay of methylated gene RARbeta2 in circulating DNA of blood from patients with lung cancer as a potential prognostic marker].

Blood-based methylated DNA gene RARbeta2 in circulating plasma (cir DNA) and one associated with blood cell surface were assayed in patients with non small cell lung cancer before and after combined treatment. The levels in both appeared to be significantly higher than in healthy subjects. Enhanced levels prior to treatment were associated with greater advancement of the disease and unfavorable prognosis (overall survival). After two courses of neoadjuvant therapy plus surgery methylation indices fell down to match those in healthy subjects. Our data may be instrumental in working out additional criteria to be used in diagnosis, prognosis and follow-up of patients with non small cell lung cancer.

[The peculiarities of rat tissue reactions to intraperitoneal implants made out of biodegradable polyhydroxyalkanoates].

The reaction of rat tissues to intraperitoneal placement of implants made out of biodegradable polyhydroxyalkanoates (PHA), was studied at different time points after the operation by the methods of light microscopy. It was found that after intraperitoneal PHA implant placement, the active adhesive process started leading to formation of fibrous adhesions between PHA implants and intestinal loops. When PHA implants were used in the form of films, they became surrounded by a thick fibrous capsule. As a result of PHA implant placement in the form of ultrathin fibers, the extensive foreign body granulomas with perifocal inflammation and sclerosis of surrounding tissues were formed. In these granulomas the polymer fragmentation and phagocytosis by macrophages with formation of giant cells of foreign body occured. It is concluded that PHA implants are not biodegradable and induce tissue reactions similar to those caused by other foreign bodies.

[Molecular-genetic markers in lung cancer diagnostics].

The major approaches to different lung cancer marker development are outlined in the review, including genetic, epigenetic, protein, transcryptomic, proteomic, metabolic, and miRNA markers. As far as epigenetic changes are among the earliest events in malignant transformation, methylated markers are thoroughly discussed. Special attention is given to minimally invasive tumor markers, which could be detected in easily accessible biological fluids, because they can be useful for screening and early diagnostics of cancer (before its clinical manifestation) as well as for verification of standard methods of diagnostics. Extracellular nucleic acids, circulating in blood (cirNA), are highlighted as the potential source of material for the early lung cancer diagnostics, prediction of antitumor treatment efficiency, post-treatment monitoring and disease prognosis.

[Possibile application of X-ray and high resolution CT in pneumoconiosis management].

The article covers results of clinical and roentgenologic data analysis. The data were obtained in the study that covered 447 pneumoconiosis patients, 75 of which were subjected to high resolution CT. If compared to chest X-ray, high resolution CT helps more precise forecast of further course in pneumoconiosis.

[Downregulation of activated leukemic oncogenes AML1-ETO and RUNX1(K83N) expression with RNA-interference].

In the present study we have applied the siRNA approach for substantial reduction of AML1-ETO and RUNX1 (K83N) expression, which are frequently found in the leukemic cells. We have designed small hairpin RNAs (shRNA) for targeting AML1-ETO oncogene and a region close to the 5'-untranslated region of mRNA for the mutant RUNX1 (K83N) oncogene and expressed the shRNAs in lentiviral vectors. We report a stable reduction in expression of the oncogenes following the introduction of shRNAs into cells.

[Application of a two-layer dynamic self-regulating alloplasty in treatment of patients for giant postoperative abdominal hernia].

A new technique of two-layer dynamical abdominal wall alloplasty was applied in 2005-2008 in 10 patients, ageing (55.3 +/- 12.6) yrs old at average, for giant postoperative abdominal hernia, based on a G. Valenti principle of dynamical self-regulating prosthesis and the method of temporary closure of operation wound, according to Wittmann Patch procedure. It was proved, that introduction of original technique of a two-layer dynamical self-regulating abdominal wall alloplasty permits to escape postoperatively the abdominal compartment syndrome development.

[Cholesterol-modified anti-MDR1 small interfering RNA: uptake and biological activity].

Small interfering RNAs (siRNA) are considered to be potent agents for specific gene silencing, but troubles in delivery of siRNA into cells limit their biomedical application. An accumulation of siRNA coupled with cholesterol residue at the 5'-end of the "passenger" strand (chol-siPHK) was investigated in HEK293, HepG2, SC1, and KB-8-5 cells. In the absence of a transfectant levels of both unmodified and chol-siRNAs were very low, whereas transfectant substantially increased transfection rate in all cell lines; in HEK293, SC1, and KB-8-5 cells transfection efficiency for the chol-siRNA being higher than that for the corresponding siRNA. Multiple drug resistance phenotype reversing activity of anti-MDR1-siRNAs targeted to the 557-577 region of MDR1 gene mRNA was investigated in KB-8-5 cancer cells. The chol-siRNA induced cancer cells' death in the presence of vinblastine doses tolerated before more effectively than the conventional siRNA did.

[Preperitoneal alloplasty of inguinal canal].

The results of treatment of 221 patients for inguinal hernia, including preperitoneal hernioplasty in 117 and hernioplasty according to Lichtenstein method in 104 of them, were analyzed. After the operation the testis shells watering had occurred in 6 patients, the postoperative cicatrix infiltrate--in 6, operative wound hematoma--in 4. The hernia recurrence had occurred, while fol-lowing patients up from 6 months till 4 years, in one patient only after operation, performed according to Lichtenstein method. In patients, to whom preperitoneal plasty of inguinal canal was per-formed, a specific complications, associated with the operation performance, were absent. Preperitoneal plasty secures a safe strengthening of hernial gates. The net implant fixation in preperi-toneal space permits to escape the feeling of a "foreign body" pres-ence in inguinal area of the patients.

[Mechanism of cytotoxicity of artificial ribonucleases in various human cancer cell lines].

The ability of artificial ribonucleases to cause in the concentration-dependent manner death of cancer cells has been studied. The cytotoxic activity of artificial ribonucleases is observed at rather low concentration of these compounds (10(-5) M). Analysis of the mechanism of artificial ribonucleases cytotoxicity revealed that compounds under the study exhibit membranotropic activity in addition to ribonucleases activity found earlier. This activity is responsible for effective penetration of these compounds inside cells. The results obtained show that artificial ribonucleases induce cell death via damage of cells membrane, detachment of plasmalemma and derangement its macromolecular organization. In the case of short-term exposure of cells to the compounds, cells, even with damaged membrane, survive.