Eksperimental'naia onkologiia最新文献

The intracellular Na+/K+ ratio was studied for its effect on expression gene beta-actin and oncogene c-fos and activity of these genes during the mitotic cycle in ascites cells of leukemia P-388 and Ehrlich tumour. It was established that gene beta-actin was activated at high and low ratios of Na+/K+, while c-fos only at high ones. The expression of these genes during the mitotic cell cycle was due to changes in the intracellular Na+/K+ ratio. The obtained data showed an important role of intracellular homeostasis of monovalent cations in regulation of gene expression during the mitotic cell cycle.

The data on the changes in the isoenzyme spectrum of pepsinogen-pepsin inversely correlating with the development and retaining of the malignant condition of gastric mucosa in human and animals are reviewed. The results of the molecular-genetic studies of gastric carcinogenesis, in particular the role of protooncogenes--oncogenes in this process are presented.

It was found that repeated transplantation of ACATOL strain cells resulted in a loss of their sensitivity to growth-stimulating effect of pentagastrin. The effect of gastrin receptor antagonist proglumide, on ACATOL cells growth was inconstant. ACATOL tumor was sensitive to VIP and glucagon in vitro (as shown by adenylate cyclase activity assay), that makes the model promising for selecting potent hormone drugs against colorectal cancer.

A comparative study of immunological reactivity of healthy volunteers and cancer patients with different stages of the disease was carried out. The study of 8 types of suppressor cells, chemoreceptor sensitivity and blast transformation of lymphocytes, natural killer cells, the level of immunoglobulins, regulatory subpopulation of lymphocytes, etc., has revealed several alterations in regulatory and effector links of immunity in the patients with late stages of the disease. The detailed immunological monitoring in the course of varying schemes of treatment is emphasized.

Mouse skin allografts and intramuscular BRO human melanoma xenografts were successfully established in phenotypically normal mice after inducing immunological tolerance in the recipients. Tolerance was achieved by inoculating allogenic embryonic liver cells after the whole-body irradiation. No immunological rejection was evident in BRO xenografts for 34 days after transplantation. During this period the BRO cells invaded neighboring tissues and formed distant micrometastases in the lungs.

Certain expression regularities of different markers in human breast cancer cells are demonstrated. Monomorphic determinants of HLA class II antigen are detected only in case of HLA class I expression and cancer-embryonal antigen (CEA); the latter is combined with HLA class I and ICO-84 antigens at a significantly higher rate. The expression effect of CEA and HLA-DR on the metastatic spreading rate of regional lymph nodes is marked. A heterogeneity of the single tumour and in patients with malignant breast cancer is determined by the presence of the "leucocytic" antigens and CEA. In parallel studies monoclonal antibodies (MAB) HMFG-1 and a common epithelial antigen are assayed. The antigen interacting with MAB HEA-125 is characterized by the monomorphic expression.

The activity of glutathione system enzymes exposed to nitroso-compound (NC) precursors in small doses for 12 months and preliminary injection of vitamin A have been studied. The histo- and biochemical examinations have revealed a pronounced increase in the enzyme activity exposed of NC precursors and a slight increase when injecting preliminary vitamin A.

The expression of BLV antigens has been studied in cells of virus-producing culture FLK 44/2. Monitoring of reactivity of antiviral polyclonal and monoclonal antibodies with cells of the virus-producing culture performed immunocytochemically has revealed the heterogeneity of the cell population both by different forms and by the level of viral expression. A change in the amount of cells reacting with antiviral antibodies during development of the population in vitro is considered as a result of the cell growth cycle-dependent process.

The ornithine decarboxylase (ODC) activity and concentration of polyamines have been studied in small and large intestine during 1,2-dimethylhydrazine-induced carcinogenesis in rats. Changes in the polyamine biosynthesis consisting both in enhanced ODC activity and an increase of the intracellular content of putrescine, spermidine and spermine. Process of the polyamine synthesis activation proceeds in two phases: the most expressed and similar changes in polyamine metabolism factors have been observed at early (the 1st month) and late (the 5th-6th months) stages of carcinogenesis. It is supposed that intensification of the polyamine synthesis is a typical feature of malignization in the gastrointestinal tract.

Among patients with Hodgkin's disease 30 cases of the family disease were revealed during 1972-1988. The occurrence of family pairs of patients with Hodgkin's disease suggests a heritable anomaly or inheritance of a gene predisposing for this disease. In cases of contacts with second degree relatives and children from a single family, one cannot exclude a role of environmental factors and a concurrent transfer of the infectious factor. However, cases of family Hodgkin's disease might be due to a pure coincidence.