[Expression of HIV-1 Reverse Transcriptase in Murine Cancer Cells Increases Mitochondrial Respiration].

Changes in metabolic pathways are often associated with the development of a wide range of pathologies. Increased glycolysis under conditions of sufficient tissue oxygen supply and its dissociation from the Krebs cycle, known as aerobic glycolysis or the Warburg effect, is a hallmark of many malignant neoplasms. Identification of specific metabolic shifts can characterize the metabolic programming of individual types of tumor cells, the stage of their transformation, and predict their metastatic potential. Viral infection can also alter the metabolism of cells to support the process of viral replication. Infection with human immunodeficiency virus type 1 (HIV-1) is associated with an increased incidence of various cancers, and for some viral proteins a direct oncogenic effect was demonstrated. In particular, we showed that the expression of HIV-1 reverse transcriptase (RT) in 4T1 breast adenocarcinoma cells increases the tumorigenic and metastatic potential of cells in vitro and in vivo by a mechanism associated with the ability of RT to induce reactive oxygen species in cells (ROS). The aim of this work was to study the molecular mechanism of this process, namely the effect of HIV-1 RT on the key metabolic pathways associated with tumor progression: glycolysis and mitochondrial respiration. Expression of HIV-1 RT had no effect on the glycolysis process. At the same time, it led to an increase in mitochondrial respiration and the level of ATP synthesis in the cell, while not affecting the availability of the substrates, carbon donors for the Krebs cycle, which excludes the effect of RT on the metabolic enzymes of cells. Increased mitochondrial respiration was associated with restoration of the mitochondrial network despite the RT-induced reduction in mitochondrial mass. Increased mitochondrial respiration may increase cell motility, which explains their increased tumorigenicity and metastatic potential. These data are important for understanding the pathogenesis of HIV-1 infection, including the stimulation of the formation and spread of HIV-1 associated malignancies.

Resistance of THP-1 Leukemia Cells Infected with Cytomegalovirus to Anti-tumor Antibiotic Doxorubicin and Restoration of the Sensitivity by Inhibitors of the PI3K/AKT/mTOR Molecular Pathway.

Results obtained showed that infection with HCMV prevented the death of THP-1 cells treated with DOX in both active and latent forms of infection. In the presence of mTOR inhibitors (rapamycin and Torin2), the sensitivity of the infected cells to DOX was restored. Rapamycin inhibited the expression of the HCMV protein IE1-p72 and increased sensitivity to DOX. Molecular targets for the creation of new drugs for the treatment of leukemia in patients infected with HCMV were determined.

[Phosphoramidate derivatives of acyclovir--herpes virus replication inhibitors].

A number of new phosphoramidates of acyclovir--compounds of interest as anti-virals against resistant strains of virus herpes was synthesized. Several methods of synthesis of these compounds were suggested. Optimal method appeared to be the obtaining of phosphoramidates through the phosphomonocloride with its subsequent treatment with various amines. Two compounds have shown moderate activity against HSV-1.

Hepatitis C virus helicase/NTPase: an efficient expression system and new inhibitors.

A method has been developed for obtaining a full-length protein NS3 of hepatitis C virus with the yield of 6.5 mg/liter of cell culture, and conditions for measuring its NTPase and helicase activities have been optimized. The helicase reaction can proceed in two modes depending on the enzyme and substrate concentration ratio: it can be non-catalytic in the case of enzyme excess and catalytic in the case of tenfold substrate excess. In the latter case, helicase activity is coupled with NTPase and is stimulated by ATP. A number of NTP and inorganic pyrophosphate analogs were studied as substrates and/or inhibitors of NS3 NTPase activity, and it was found that the structure of nucleic base and ribose fragment of NTP molecule has a slight effect on its inhibitory (substrate) properties. Among the nucleotide derivatives, the most efficient inhibitor of NTPase activity is 2 -deoxythymidine 5 -phosphoryl-beta,gamma-hypophosphate, and among pyrophosphate analogs imidodiphosphate exhibited maximal inhibitory activity. These compounds were studied as inhibitors of the helicase reaction, and it was shown that imidodiphosphate efficiently inhibited the ATP-dependent helicase reaction and had almost no effect on the ATP-independent duplex unwinding. However, the inhibitory effect of 2 -deoxythymidine 5 -phosphoryl-beta,gamma-hypophosphate was insignificant in both cases, which is due to the possibility of helicase activation by this ATP analog.

[The synthesis of imidodiphosphoric acid derivatives as potential substrates in the pyrophosphorolysis reaction].

The preparation conditions for dichlorophosphinylphosphorimidic trichloride were optimized. It was used in the synthesis of esters of imidodiphosphoric acid. The interaction of the trichloride with amines resulted in the corresponding amidodiphosphates rather than in the expected amides of imidodiphosphoric acid.

A new approach to the synthesis of optically active alkylated adenine derivatives.

A new synthesis of chiral acyclic nucleoside and nucleotide analogues starting from d(-)- or l(+)-riboses was proposed. Antiviral properties of the synthesized compounds towards the pox virus family were evaluated.

[The effect of pyrophosphate analogues on the inorganic pyrophosphatase from Escherichia coli]. / Vliianie analogov pirofosfata na aktivnost' neorganicheskoi pirofosfatazy E. coli.

The effect of inorganic pyrophosphate analogues on the enzymic activity of inorganic pyrophosphatase from E. coli was studied. Hypophosphoric and diphosphonic acids were shown to inhibit inorganic pyrophosphatase, whereas pyrophosphorous acid exerts almost no effect on the hydrolysis of inorganic pyrophosphate. The English version of the paper: Russian Journal of Bioorganic Chemistry, 2002, vol. 28, no. 6; see also http://www.maik.ru.

[A photoreactive analogue of 2'3'-dideoxyuridine 5'-triphosphate: preparation and use for photoaffinity modification of human replication protein A]. / Fotoreaktsionnosposobnyi analog 2',3'-didezoksiuridin-5'-trifosfata: poluchenie i ispol'zovanie dlia fotoaffinnoi modifikatsii faktora replikatsii A cheloveka.

A new reagent for photoaffinity modification of biopolymers, 5-[E-N-(2-nitro-5-azidobenzoyl)-3-amino-1-propen-1-yl]-2',3'-dideoxyuridine 5'-triphosphate (NAB-ddUTP), was synthesized. Like a similar derivative of 2'-deoxyuridine 5'-triphosphate (NAB-dUTP), it was shown to be able to effectively substitute for dTTP in the synthesis of DNA catalyzed by eukaryotic DNA polymerase beta and to terminate DNA synthesis. A 5'-32P-labeled primer with a photoreactive group at the 3'-terminus was derived from NAB-ddUTP and used for photoaffinity labeling of the human replication protein A (RPA). The covalent attachment of RPA p32 and p70 subunits to the labeled primers was demonstrated. NAB-ddUTP is a promising tool for studying the interaction of proteins of the replicative complex with NA in cellular extracts and living cells during the termination of DNA synthesis.

P-(alkyl)-nucleoside 5'-hydrogenphosphonates as depot forms of antiviral nucleotide analogues.

P-(Alkyl)esters of AZT 5'-hydrogenphosphonate were synthesized and their stabilities in the phosphate buffer and human serum were evaluated. The esters bearing residues of primary and secondary alcohols were degraded to give AZT, whereas those containing tertiary alkyl groups yielded AZT 5'-hydrogenphosphonate. The corresponding derivatives of d2A and d4T showed the same properties.