[Anticancer activity of oxovanadium compounds].

Cytotoxic and antitumor activity of the biligand vanadyl derivative of L-malic acid (bis(L-malato)oxovanadium(IV) (VO(mal)2) was investigated in comparison with inorganic vanadium(IV) compound--vanadyl sulfate (VOSO4) and also with oxovanadium monocomplex with L-malic acid (VO(mal)) and vanadyl biscomplex with acetylacetonate. In this purpose the effect of vanadyl compounds on growth of normal human skin fibroblasts and tumor cells of different lines: mouse fibrosarcoma (L929), rat pheochromocytome (PC12), human liver carcinoma (HepG2), virus transformated mouse fibroblast (NIN 3T3), virus transformated cells of human kidney (293) were investigated. The results showed that VO(mal)2 was not toxic for normal human skin fibroblasts but considerably inhibited growth of cancer cells in culture. Cytotoxic antitumor effect of vanadium complexes was found to be dependent on incubation time and concentration and on type of cells and nature of ligands of the central group of the complex (VO2+). These studies provide evidence that VO(mal)2 may be considered as a potential antitumor agent due to its low toxicity in non-tumor cells and significant anticancer activity.

[Antitumor activity of L-asparaginase from Erwinia carotovora from against different leukemic and solid tumours cell lines].

We have studied dose- and time-dependent antitumor and cytotoxic effects of Erwinia carotovora L-asparaginase (ECAR LANS) and Escherichia coli L-asparaginase (MEDAC) on human leukemic cells and human and animal solid tumor cells. We determined the sensitivity of tumor cells to L-asparaginases, as well the effect L-asparaginases on cell growth rate, protein and DNA synthesis per se and with addition of different cytostatics. The data obtained demonstrated that ECAR LANS L-asparaginase suppressed growth of all tested solid tumor cells. Evaluation of leukemic cell number after treatment with L-asparaginases for 24, 48 and 72 h demonstrated that asparagine deficiency did not kill cells but stopped normal cell division and had no effect on protein and DNA synthesis. Cytofluorometric study of solid and leukemic cells demonstrated that the treatment with L-asparaginase for 72 h did not change cell cycle phase distribution and did not increase the number of apoptotic cells. The HL-60 cell line was only exemption. At the same time, cells treatment with L-asparaginase and doxorubicin combination leaded to increase of apoptotypical cell number to 60% for MCF7 cells, to 40% for Jurkat cells and to 99% for HL-60 cells. We have excluded apoptosis as main reason for tumor cell death after asparaginase treatment because multi resistant Jurkat/A4 cells have been asparaginase sensitive. We have not found ECAR LANS L-asparaginase effect on normal human fibroblasts growth ability and we had come to conclusion that enzyme cytotoxcisity related only with asparagine deficiency.

[Antitumor activity of L-asparaginase from Yersinia pseudotuberculosis].

The cytotoxic activity of L-asparaginases from Yersinia pseudotuberculosis and from Erwinia carotovora were investigated in vitro using several tumor cells lines: Jurkat and Molt-4 (human T-lymphoblastic leukemia), MCF-7 (human breast adenocarcinoma), LnCap (human prostate carcinoma), NGUK1 (rat Gasser node neurinoma). E. coli L-asparaginase produced by "Medak" (Germany) was used as a reference. The cell growth inhibition data indicate that Y. pseudotuberculosis L-asparaginase significantly inhibits growth of leukemic and solid tumor cells. These results allow us to conclude that this L-asparaginase can be used for the development of new preparations for the therapy of different types of tumors.

[Transfection of eucaryotic cells using cytochrome CYP450 2B6 gene: sensitivity to cyclophosphamide]. / Transfektsiia éukarioticheskikh kletok genom tsitokhroma CYP450 2B6: poiavlenie chuvstvitel'nosti k tsiklofosfamidu.

Sensitivity of 293 human epithelial kidney cells transfected by human cytochrome CYP450 gene to cyclophosphamide was investigated. Transfection was carried out by plasmid DNA containing CYP2B6 gene complexed with cationic liposomes. Liposomes were prepared from mixture of cationic lipids and cholesterol at different molar ratios. Experimental protocol included the following steps: transfection of epithelial kidney cells by complexes of plasmid DNA-cationic liposomes, clone selection in the medium with antibiotic Geneticin G418, selected clone harvesting and their treatment by cyclophosphamide as following cytotoxicity evaluation. It was shown that addition of 0.25 mM of cyclophosphamide resulted in death of 40-45% transfected cell population.

[Hypoglycemic effect of an extract from Aronia melanocarpa leaves]. / Issledovanie gipoglikemicheskogo deistviia ékstrakta iz list'ev Aronia melanocarpa.

The action of extract from Aronia melanocarpa leaves to blood glucose level was investigated. It was shown that incorporated into drinking water and administrated intraperitoneally, the extract significantly reduce the blood glucose level of streptozotocin (STZ)-diabetic and normal rats.

[Stimulation of glucose uptake in PC 12 and L 929 cells by extracts from Aronia melanocarpa leaves]. / Stimuliatsiia pogloshcheniia gliukozy kletkami PC 12 i L 929 ékstraktom iz list'iev Aronia melanocarpa.

The ability of extract from Aronia melanocarpa leaves to increase glucose uptake was investigated. It was shown, that the extract stimulated glucose uptake by cells PC12 and L 929 at the concentration close to native insulin.

[The prolonged action of an insulin peptidomimetic by the substitution of L-amino acid for its D-isomer]. / Uvelichenie vremeni deistviia peptidomimetika insulina putem zameny L-aminokislotnykh ostatkov ikh D-opticheskimi izomerami.

The synthesized decapeptide represents functionally important site for binding to the insulin receptor. Amino acid residues at position, 1-8 correlate with B-chain of insulin at position B19-B26, and the residues at position 9-10 correlate with A-chain at position A20-A21. The new peptide was obtained by substitution of two aromatic L-amino acid residues (B24 and B26) for their D-optical isomers. These peptides were tested with cell cultures L929 and PC12 (glucose uptake). Increased concentration of peptides correlated with stimulation of glucose uptake by cells. Studies carried out on animals with streptosotocine-caused diabetes showed that, synthesized peptides were able to decrease glucose level in blood, but decapeptide with D amino acid showed a more pronounced effect compared to the decapeptide with L amino acid.

[Specific binding and uptake of peptide ligand modified liposomes by PC12 cells]. / Issledovanie spetsificheskogo sviazyvaniia i pogloshcheniia modifitsirovannykh peptidnym ligandom liposom kletkami PC12.

Possible employment of cell-specific peptide for the specific adsorption and uptake by cells. It was shown, that apoprotein E 139-158 peptide increases liposomal binding followed by receptor-mediated endocytosis by cells PC12.

[A synthetic fragment of insulin with insulin-like biological activity]. / Sinteticheskii fragment insulina s insulinopodobnoi biologicheskoi aktivnost'iu.

We have used computer modeling of insulin 3-D structure and experimental data about action of site point mutation on insulin activity to design functionally important domain with signaling activity and synthesized peptide than might be sufficient for the binding to insulin receptor. The designed and synthesized peptide consist of ten residues and may be obtained in two forms: oxidized and reduced (with or without disulfide bond). The synthesized decapeptide peptide represents functionally important site for binding to the insulin receptor. Amino acid residues at position 1-8 correlate with B-chain of insulin at position (B19-B26). Residues at position 9.10 correlate with A-chain at position A-10-A21. This peptide was tested with cell culture L-929 (glucose uptake) in comparison with bioactive commercial peptide (R-G-FF) and insulin. It was shown that synthesized peptide exhibit biological activity at molar concentration 0.01-1 mkM. Our results successfully demonstrate the synthetic insulin fragment have insulin-like biological activity.

[Stimulation of regenerative processes and correction of the functional activity of the liver in its partial resection and toxic lesions]. / Stimuliatsiia protsessov regeneratsii i korrektsiia funktsional'noi aktivnosti pecheni pri ee chastichnoi rezektsii i toksicheskikh porazheniiakh.

The effects of hepatotropic growth factors (HGFs) and phospholipid drugs on the recovery of functions and the regeneration of the rat liver were studied in CC14-induced toxic damage and after partial hepatectomy (PHE). HGFs isolated from the cytoplasmic cells of the regenerating liver, as well as from the liver of the animals given prodigiozan and from the media taken after culturing the explants of the regenerating liver were found to stimulate DNA synthesis and hepatocytic proliferation following PHE and in the cirrhotic liver. Prodigiozan was shown to induce the formation of HGFs not only in the rat liver following PHE, but in the liver of intact animals. It was established that the covalently binding complex of albumin and bilirubin stimulated the synthesis of proteins and DNA in the regenerating liver, but non-covalently binding complex inhibited these processes. When CC14 was administered to the animals, the two complexes enhanced the reparative synthesis of DNA, without changing the level of replicating synthesis, the non-covalently binding complex completely eliminating the single-strand breaks in DNA. Phospholipid agents containing soybean and sunflower phosphatidylcholines increased the synthesis of RNA and albumin, which were decreased due to exposure to CC14 and had the property of stimulating the synthesis of total DNA and considerably enhancing that of mitochondrial DNA.

[The effect of phosphatidylcholine on repair processes in liver cells in acute CCl4 damage]. / Vliiane fosfatidilkhonlina na reparatsionnye protsessy v kletkakh pecheni pri ee ostrom povrezhdenii CCL4.

Effect of phosphatidylcholine, isolated from soy beans and sunflower seeds for laboratory use, on synthesis of RNA, DNA, albumin and content of newly synthesized mRNA in polyribosomes was studied in hepatocytes after chemical hepatectomy produced by single administration of CCl4 into rats; histological and histochemical studies of liver tissue were also carried out. Phosphatidylcholine from these plants was found to prevent hepatocyte dystrophy and necrosis development, to activate the macrophage response and to stimulate reparation inducing synthesis and secretion of the tumor necrosis factor. The rate of highly labelled RNA synthesis, mainly mRNA, decreased in liver tissue of rats treated with CCl4, was increased approximately 2-fold after the phospholipid administration. The phospholipid from soy beans restored the albumin synthesis as well as the content of newly synthesized mRNA in rat polyribosomes, while phosphatidylcholine from sunflower seeds restored effectively the mitochondrial DNA synthesis. Promising application of these phosphatidylcholines as hepatoprotectors is discussed.

[The effect of covalently and noncovalently bound complexes of albumin with bilirubin on DNA and protein synthesis in liver and spleen of rats subjected to splenectomy and partial hepatectomy]. / Vliianie kovalentno i nekovalentno sviazannykh kompleksov al'bumina s bilirubinom na sintez DNK i belka v pecheni i selezenke krys so splenéktomiei i chastichnoi gepatéktomiei.

Noncovalently bound complexes of albumin and bilirubin were found to stimulate DNA and protein synthesis in partially hepatectomized regenerating rat liver tissue, while the covalently bound complex inhibited both these synthesis types in liver tissue after partial hepatectomy. Splenectomy of intact rats caused an induction of DNA and protein synthesis in liver tissue but partial hepatectomy decreased drastically the synthesis rate in spleen, thus suggesting that humoral factors stimulating the proliferation response in liver and spleen tissues were developed after spleen- and hepatectomies. The covalently bound albumin and bilirubin complex did not affect the rate of DNA and protein synthesis in liver tissue of splenectomized rats, while the complex with noncovalent bonds restored the rate of DNA and protein synthesis in the spleen of rats with partial hepatectomy. Only the noncovalently bound complex of albumin and bilirubin exhibited the properties inherent in hepatotropic growing factor whereas albumin administration was not effective. Possible structure and action of the noncovalently bound albumin and bilirubin complex are discussed.

[Role of polypeptides of pancreatic juice in the healing of intestinal anastomosis]. / Rol polipeptidov pancreaticheskogo soka v zazhivlenii kishechnykh anastomozov.

The possibility of using the polypeptide fraction of the pancreatic juice to accelerate healing of an intestinal anastomosis was studied in experiments. It was shown that the pancreatic polypeptides possess the properties of potential growth factors: after a single injection of these substances into the zone of the anastomosis during the operation, the synthesis of DNA and proteins in the tissues of the anastomosed intestinal segments essentially increases, which is evidence of stimulation of cell proliferation. Intensification of the proliferative processes in the tissues of the anastomosis improves the qualitative characteristics of the muscular suture-mechanical strength and biological air-tightness. The use of pancreatic polypeptides for acceleration of healing of an anastomosis formed in peritonitis showed this nontraditional method of protection of the intestinal suture to be very effective.

[The effect of chronic butyphos poisoning on protein and nucleic acid synthesis in various rat organs and activity of blood cholinesterase]. / Vliianie khronicheskoi intoksikatsii butifosom na sintez belka i nukleinovykh kislot v razlichnykh organakh krys i aktivnost' kholinésterazy krovi.

Two doses of butyphos (1/10 and 1/50 LD50) were administered into rats within 6 months. Content of DNA was distinctly decreased in liver and kidney tissues within the first 2 weeks of the pesticide administration. Then DNA synthesis was increased 2-fold in liver tissue and remained high during all the 6 months of intoxication. Protein synthesis was increased in liver tissue within 3 months of the administration and remained elevated up to the end of experiment. High rate of protein synthesis, found in kidney and spleen tissues at the initial steps, was markedly decreased within 6 months. Content of DNA and RNA was decreased in the tissues studied within 1 month of the intoxication and restored within 3 months, while it remained at considerably lower level in liver and spleen tissues as compared with control values. Cholinesterase activity was lowered by 90% in blood within 11 weeks with the subsequent increase; but in the experimental group intoxicated with butyphos at 1/10 LD50 the enzymatic activity constituted only 60% of control values within 6 months. Histological study showed development of necrodystrophy in liver tissue and of fibroplastic glomerulonephritis in kidney. The deteriorating effect of butyphos on cellular genome functions appears to relate not only to its cytotoxicity but also to the cancerogenic and mutagenic properties of the pesticide.

[The regulation of DNA synthesis by fibronectin and its proteolytic products in the skin fibroblasts of healthy donors and patients with systemic scleroderma and rheumatoid arthritis]. / Reguliatsiia sinteza DNK fibronektinom i produktami ego proteoliza v fibroblastakh kozhi zdorovykh donorov i bol'nykh sistemnoi sklerodermiei i revmatoidnym artritom.

To study the effect of fibronectin isolated from plasma and culture media and the effect of its tryptic hydrolyzates on DNA synthesis, cultured skin fibroblasts of healthy donors and these of patients with systemic scleroderma (SSD) and rheumatoid arthritis (RA) were employed. It was shown that both fibronectin and total products of its proteolysis markedly stimulated DNA synthesis only in skin fibroblasts of patients with SSD. Fibronectin fragments inhibited DNA synthesis in all fibroblast strains studied. The effect of fibronectin and all its Gel fragments on the DNA synthesis in skin fibroblasts of patients with SSD was dose-dependent. The activity of total fibronectin tryptate, Gel-fragment-free tryptate, and Gel fragments themselves depended on the duration of fibronectin proteolysis, i. e. on the size of the fragments obtained. Culture media collected after treatment of fibroblast monolayer with trypsin and subsequent removal of fibronectin Gel fragments had mitogenic effect on skin fibroblasts, especially on those of patients with SSD and RA. It is supposed that fibronectin Gel fragments are inhibitors of growth factors produced by fibroblasts. The results suggest that fibronectin and its fragments have an important regulatory role in fibroblast proliferation.

[Regeneration ability of ischemic liver and the effect of liver resection and extracts stimulating proliferation]. / Regeneratsionnaia sposobnost' ishemizirovannoi pecheni i vliianie na nee rezektsii i ékstraktov, stimuliruiushchikh proliferatsiiu.

DNA synthesis was studied in liver nuclei of Wistar rats after 30% liver tissue resection, 2 hr ischemia of 70% liver tissue or 2 hr ischemia of 70% liver tissue with resection of intact lobes. DNA synthesis was markedly increased in ischemic lobes and was especially high in ischemic lobes if simultaneous resection of intact lobes occurred; maximum of the synthesis was observed within 32 hrs after the operation. Proliferation stimulating extracts, isolated from liver tissue within 48 hrs after the resection or after ischemia, intensified the regenerating processes in the resected liver tissue; the first preparation (from resected liver tissue) exhibited the most distinct effect as compared with the second extract (from ischemic liver tissue). Proliferation stimulating extracts did not affect the cytochrome P-450, content of which was decreased after resection and ischemia. The data obtained suggest the important role of proliferation stimulating factors in regeneration of liver tissue after ischemia or resection; these factors proved to be possible to isolate from ischemized and reperfused liver tissue; the medicinal effect of resection was shown.