[Antineoplastic mechanisms of niclosamide-loaded nanoparticles in human colorectal cancer cells]. / Molekuliarnye mekhanizmy protivoopukholevoi aktivnosti polimernoi formy niklozamida v otnoshenii kletok kolorektal'nogo raka.

Using poly(lactic-co-glycolic) acid we developed a polymeric form of niclosamide (PFN) and investigated molecular mechanisms underlying its antitumor activity against human colorectal cancer cell lines (SW837, Caco-2, COLO 320 HSR). PFN was shown to be more cytotoxic against cancer cells and less cytotoxic against normal cells (human embryonic lung fibroblasts) as compared to niclosamide. Both niclosamide and its polymeric form caused mitochondrial damage (evaluated as a decrease in rhodamine 123 accumulation) and increased the levels of reactive oxygen species, particularly mitochondrial superoxide, resulting in the oxidative damage to biomolecules. Furthermore, niclosamide and PFN induced G0/G1 cell cycle arrest.

Targeted delivery of doxorubicin: drug delivery system based on PAMAM dendrimers.

Polyamidoamine (PAMAM) dendrimers of the second generation (G2) are branched polymers containing 16 surface amino groups that allow them to be used as universal carriers on creating systems for drug delivery. G2 labeled with fluorescein isothiocyanate (FITC) efficiently bound with the surface of tumor cells at 4°C and was absorbed by the cells at 37°C. The covalent binding to G2-FITC of a vector protein, a recombinant fragment of the human alpha-fetoprotein receptor-binding domain (rAFP3D), increased the binding and endocytosis efficiency more than threefold. Covalent conjugates of G2 with doxorubicin (Dox) obtained by acid-labile linking of cis-aconitic anhydride (CAA) without the vector protein (G2-Dox) and with the vector protein rAFP3D (rAFP3D-G2-Dox) were accumulated by the tumor cells with high efficiency. However, a selective effect was observed only in rAFP3D-G2-Dox, which also demonstrated high cytotoxic activity against the human ovarian adenocarcinoma SKOV3 cells and low cytotoxicity against human peripheral blood lymphocytes. Based on these results, rAFP3D-G2 conjugate is promising for selective delivery of antitumor drugs.

A new system for targeted delivery of doxorubicin into tumor cells.

The use of vector molecules for the targeted delivery of antitumor drugs provides their selectivity for cancer cells. The recombinant receptor-binding fragment of alpha-fetoprotein (rAFP3D) was used as a vector molecule. The specific receptor of alpha-fetoprotein is a universal tumor marker, being expressed on the surface of many tumor cells, but not in normal human tissues. And rAFP3D includes the receptor binding cite of AFP. A three-component delivery system including vector protein rAFP3D, PAMAM G2 dendrimer and antitumor antibiotic doxorubicin (Dox) was synthesized. The attachment of two dendrimer molecules to the vector protein did not affect the effectiveness of rAFP3D binding to AFP receptor on the surface of tumor cells nor the effectiveness of receptor-mediated endocytosis. Dox was conjugated with G2 via cis-aconitic anhydride (acid labile linker). The in vitro Dox release study showed that the conjugate was stable at neutral pH but was labile at pH<6. The Dox release was correlated with the intracellular distribution of conjugate in tumor cells. The rAFP3D-G2-Dox conjugate demonstrated a high cytotoxic activity against human ovarian adenocarcinoma cell lines: Dox-sensitive SKOV3 cells and Dox-resistant SKVLB cells and was low-toxic against human peripheral blood lymphocytes. Based on our findings, we may conclude that it is possible to significantly increase the effectiveness of Dox delivery to tumor cells by using the targeted delivery system comprising the recombinant third domain rAFP3D as a vector molecule.

Composition and antimicrobial activity of the skin peptidome of Russian brown frog Rana temporaria.

A nano-HPLC-ESI-OrbiTrap study involving HCD and ETD spectra has been carried out to clarify the composition of the skin peptidome of brown Russian frogs Rana temporaria. This approach allowed determinantion of 76 individual peptides, increasing 3-fold the identified portion of the peptidome in comparison to that obtained earlier with FTICR MS. A search for the new bradykinin related peptides (BRPs) was carried out by reconstructing mass chromatograms based on the ion current of characteristic b- and y-ions. Several peptides were reported in the secretion of R. temporaria for the first time. The overall antibacterial activity of the skin secretion in general and of one individual peptide (Brevinin 1Tb) was determined using PMEU Spectrion (Portable Microbe Enrichment Unit) technology. The inhibitory effects of these peptides on Staphylococcus aureus and Salmonella enterica Serovar typhimutium were equal in scale to that reported for some antibiotics.

[Synthesis of 1-hydroxyalkyl-3-substituted ureas and thioureas as a substrates for alcohol dehydrogenase]. / Sintez 1-gidroksialkil-3-zameshchennykh mochevin i tiomochevin kak substratov alkogol'degidrogenazy.

A series of 1-(2-hydroxyethyl)- and 1-(3-hydroxyethyl)-3-substituted ureas and thioureas were synthesized. 1-(3-Hydroxyethyl)-3-acylthioureas were shown to be specific substrates for alcohol dehydrogenase in vitro.

[Synthesis and antibacterial activity of the new 9-aminoacridine, 10,11-dihydro-5H-dibenzo[b,f]azepine, polyfluoro 5,6-dihydro-1,3,5-oxadiazine derivatives]. / Sintez i issledovanie antibacterial'noi aktivnosti novykh proizvodnykh 9-aminoakridina, 10,11-digidro-5H-dibenzo[b,f]azepina, poliftorirovannykh 5,6-digidro-1,3,5-oksadiazinov.

Screening among 9-aminoacridine, 10,11-dihydro-5H-dibenz[b, f]azepine and polyfluoro 5,6-dihydro-1,3,5-oxadiazine derivatives allowed to isolate compounds with potential antibacterial activity. Schemes of the active compounds synthesis are given. The most important is the estimation of the oxydiazines activity against gram-positive microorganisms including methicillin-resistant staphylococci. Special attention is paid to the activity of iminodibenzyl derivatives against multiresistant gram-negative microorganisms.

[Synthesis of uracil and theophylline derivatives and study of their effect on glucose transport in rat hepatic cells]. / Sintez proizvodnykh uratsila i teofillina i issledovanie ikh vliianiia na transport gliukozy v kletki pecheni krys.

A series of uracil and theophyllin derivatives were synthesized. 4-Amino-1,3-dimethyl-5-nonanoylaminouracil displayed the most pronounced effect of the in vitro stimulation of the 2-deoxyglucose transport into hepatic rat cells.

[Synthesis and antiproliferative activity of a novel N-acyl derivative of doxorubicin]. / Sintez i antiproliferativnaia aktivnost' novogo N-atsil'nogo proizvodnogo doksorubitsina.

Doxorubicin was acylated with estrone 3-hemisuccinate. The modified derivative exhibited high antiproliferative activity in vitro toward cell cultures of the MCF-7 human mammary adenocarcinoma and HepG2 human hepatoma.

[Effect of fluorine-containing ethers of permetrinic acid on inactivation kinetics of sodium influx into neuroblastoma cells (NEURO-2(alpha)]. / Vliianie ftorsoderzhashchikh éfirov permetrinovoi kisloty na kinetiku inaktivatsii natrievogo toka v kletkakh neiroblastomy (NEURO-2(alpha).

A synthesis of a number of esters of (+/-)-cis, trans-3-(2,2-dichlorovinyl) -2,2-dimethylcyclopropanecarboxylic acid with polyfluorinated alcohols was carried out. Their effect on kinetics of inactivation of sodium current in neuroblastoma (Neuro-2a) cells by the patch-clamp technique in the whole-cell configuration was investigated.

[Substrate specificity of adenosylcobalamin-dependent glycerol dehydratase. Interaction with enantiomers of 1,2-propanediol]. / Substratnaia spetsifichnost' adenozilkobalaminzavisimoi glitseroldegidratazy. Vzaimodeistvie s énantiomerami 1,2-propandiola.

Adenosylcobalamin-dependent glycerol dehydratase was shown to catalyze the conversion of both enantiomers of 1.2-propanediol. The kinetic constants for the dehydration reaction of (R)- and (S)-1.2-propanediol appear to be different. The enzyme preferentially binds 1.2-propanediol in the (S)-configuration; however, the rate of (S)-1,2-propanediol dehydration is 2 times less than that of (R)-1.2-propanediol. The catalytic conversion of 1.2-propanediol enantiomers is accompanied by the enzyme inactivation. During dehydration of (R)-1.2-propanediol the enzyme is inactivated at a higher rate than during the (S)-enantiomer dehydration. The turnover number of the enzyme calculated as a ratio of the rate constants of catalysis and inactivation does not practically depend on the substrate configuration. Consequently, the changes in the configuration of the substrate, 1.2-propanediol, similarly affect the rate-limiting steps of the catalytic and inactivation processes. It is assumed that the (R)- and (S)-enantiomers of 1.2-propanediol are bound at the substrate site of glycerol dehydratase by three identical points.

[Conformational isomerization of lactate dehydrogenase complexes formed by pyruvate and coenzyme analogs]. / O konformatsionnykh perestroikakh kompleksov laktatdegidrogena3y, obrazovannykh piruvatom i analogami kofermenta.

The kinetics of LDH-catalyzed reduction of pyruvate involving APADH were studied. It was shown that under conditions of a single turnover reaction the first order rate constant is equal to 37+/-4 sec-1. The reaction rate (vo) did not change when a deutero-coenzyme was used. The relationship between vo and pyruvate concentration is hyperbolic. It is concluded that isomerization of the ternary LDH-APADH-pyruvate complex limits the reaction rate. The spectral properties and the kinetics of formation and dissociation of abortive LDH complexes with pyruvate and NAD analogs (APAD and PAAD) were studied. The participation of the carboxamide group of NAD in conformational isomerization of the LDH-NADH-pyruvate and LDH-NAD-pyruvate complexes was studied.

[The interaction of pyridine-adenine-dinucleotides containing a hydrazide group with swine muscle lactate dehydrogenase]. / Vzaimodeistvie piridin-adenin-dinukleotidov, soderzhashchikh gidrazidnuiu gruppu, s laktatdegidrogenazoi myshts svin'i

Hydrazide group of 4-substituted NAD analogues is shown to interact with functional groups of substrate-binding site in double complexes with pig muscle lactate dehydrogenase (isoenzyme M4). The lactic acid residue, which is structurally incorporated into NAD analogue, improves slightly the binding of dinucleotide, while 2,2,6,6-tetramethylpiperidine-1-oxyl residue considerably decreases the firmless of binding. The comparison of the inhibitory ability of oxamate, incotinic acid hydraxide and their spin-labelled derivatives indicates the restricted and stiff sizes of a substrate-binding site.

[Formation of adducts of pyridine nucleotides in the active center of swine lactate dehydrogenase (isoenzyme M4)]. / Obrazovanie adduktov piridinovykh nukleotidov v aktivnom tsentre laktatdegidrogenazy svin'i (izoferment M4)

Isozyme M4 of pig lactate dehydrogenase (LDH-M4) catalyzes reaction of NAD-adduct formation with a nucleophylic agent that is perhaps OH--ion. The T 1/2 of the reaction is 10-30 sec at concentration NAD 2,0-10(-3) M, LDH-M4 50 gamma/ml at pH greater than 8. Initial velocity and limit of the reaction increase at high LDH-M4, NAD and OH--ion concentrations. Pyridine-3-aldehyde and 3-acetyl pyridine analogs of NAD forms fluorescent adducts too, but at OH--ion concentration approximately 0,01 of that in the case of NAD reaction. Isoelectrical point of LDH-M4 determined by isoelectrofocusing method is 8,65 +/- 0,04 pH unit.