Nuclear localization of BCR and cortactin indicates their potential role in regulation of actin branching in nucleus.

AIM: To study cellular localization of full-length breakpoint cluster region (BCR), Pleckstrin homology domain of BCR and cortactin and determine whether they can coexist in cell nucleus. MATERIALS AND METHODS: HEK293T cell line was transfected with pECFP-BCR, pEGFP-PH and pmTagRFP-N1-CTTN using polyethyleneimine. Live cells were imaged in cell culture dishes with glass coverslip attached to the bottom with Leica SP8 STED 3D confocal microscope in the environmental chamber. Obtained images were processed and analyzed with Fiji software. RESULTS: We identified colocalization of full-length BCR and cortactin in nucleus of cell undergoing terminal phase of cell division. We did not observe nuclear localization of cortactin in non-dividing cell. Both Pleckstrin homology domain and full-length BCR exhibited cytoplasmic as well as nuclear localization. CONCLUSIONS: Colocalization of BCR with cortactin in cell nucleus indicates their potential role in regulation of actin network allowing for the maintenance of nuclear architecture and DNA integrity.

Inhibition of USP1, a new partner of Bcr-Abl, results in decrease of Bcr-Abl level in K562 cells.

AIM: To analyze interaction of ubiquitin specific peptidase 1 (USP1) with Bcr-Abl and to assess the relation between USP1 functional activity and Bcr-Abl expression in K562 chronic myeloid leukemia cells. MATERIALS AND METHODS: The interaction between USP1 and Bcr-Abl in K562 cells was analyzed by co-immunoprecipitation, Western blot analysis, and confocal microscopy. RESULTS: A direct interaction between Bcr-Abl oncoprotein and USP1 protein in K562 cells was established by co-immunoprecipitation. Immunofluorescence analysis and confocal microscopy revealed that Bcr-Abl/USP1 protein complex is formed in the cell nucleus. The inhibition of USP1 protein activity by ML323 reduced the level of Bcr-Abl oncoprotein in K562 cells. CONCLUSIONS: USP1 protein has been identified as a new protein partner of Bcr-Abl oncoprotein in chronic myeloid leukemia. The relationship between the functional activity of USP1 protein and the level of Bcr-Abl oncoprotein has been demonstrated, suggesting that the targeted inhibition of USP1 activity could be a challenging approach for reducing Bcr-Abl expression.

Colocalization of USP1 and РН domain of Bcr­Abl oncoprotein in terms of cronic myeloid leukemia cell rearrangements.

The development of chronic myeloid leukemia (CML) is the result of a reciprocal translocation between chromosomes 9 and 22 due to the emergence of Philadelphia chromosome. The product of this mutation is a hybrid oncoprotein Bcr-Abl. According to the results of mass spectrometric analysis, USP1 protein was identified as a potential candidate for interaction with the PH domain Bcr-Abl oncoprotein. Due to the deubiquitination properties, USP1 protein can prevent proteasomal degradation of Bcr-Abl oncoprotein in a cell and, consequently, contribute to its accumulation, and the progression of the disease. In this work, creating the genetic constructs, we detected the USP1 protein localization in the cell. Also, a nuclear colocalization of USP1 protein with PH domain of Bcr-Abl oncoprotein in HEK293T cells was shown. The results are important for understanding the implications of the Philadelphia chromosome emergence, and the development of new methods for CML treatment, since the recent techniques are not always effective due to the emergence of numerous mutations that cause drug resistance and relapse of the disease.

[Antiherpetic effect of RNA-tilorone molecular complex in cell culture].

The authors studied the antiviral effect of an interferonogenic yeast RNA-tilorone molecular complex (MC) compared to the Virolex, videly used antiherpetic drug, and standard interferon (IFN) alpha/beta inducer poly(I)poly(C) in Vero cells culture infected with herpes simplex type I virus (HSV-1). The tilorone contained by MC has been shown to be twice less toxic and twice more active against HSV than its free molecules. The value of chemotherapeutic index (CI) of Virolex in experiments with Vero cells reaches 2500, CI poly(I)poly(C) and MC being 324; the last value meets the requirements for promising drugs.

[Effect of interferonogenic molecular complex of yeast RNA--tilorone on DNA, RNA and protein synthesis in vitro]. / Vplyv interferonohennoho molekuliarnoho kompleksu drizhdzhova RNK--tyloron na syntez DNK, RNK ta bilka in vitro.

In the experiments in vitro using the primary mononuclear cells (MNC) culture of the human peripheral blood the influence of interferonogenic yeast RNA-tilorone molecular complex on the DNA, RNA and protein synthesis was studied. The complex was shown to inhibit the insertion of 3H-thymidine, 3H-uridine and 3H-leucine into DNA, RNA and protein of MNC total pool (by 13, 1 and 40% respectively); that was practically conformed with this synthesis inhibition upon to a natural origin polynucleotide interferon inducers--lariphan (9, 0 and 57% respectively) and ridostin (9, 0 and 56% respectively) action, and at the same time rather less than poly(I)-poly(C) (14, 5 and 62% respectively). In the case of preliminary cell stimulation by the mitogen PHA the complex revealed comitogenic action at a concentration 25 micrograms/ml, that corresponded to optimal for interferonogenesis; the increase of the doses till 100-1000 micrograms/ml lead to in the reversal effect. To proceed from mutual relation between interferonogen preparations influence on the mentioned synthesis and their cytotoxicity the conclusion was about made the complex promising usage as an interferon inducer both in vitro and in vivo conditions.

Virus-inhibitory effect of a yeast RNA-tilorone molecular complex in cell cultures.

The virus-inhibitory activity of a molecular complex (MC) of tilorone and yeast RNA was studied in vitro on three virus-cell systems: vesicular stomatitis virus (VSV) - murine fibroblast L929 cells, Venezuelan equine encephalittis virus (VEEV) - swine embryo kidney (SEK) cells and encephalomyocarditis virus (EMCV) - established piglet testicular (EPT) cells. In all these systems the MC exerted an antiviral effect similar to that of polynucleotide interferon (IFN) inducers such as poly(I)-poly(C), larifan and ridostin. The antiviral effect of the MC was similar when the compound was applied before or after virus adsorption to cells. The MC may be regarded as a perspective antiviral agent of common use.

[Comparative cytotoxic characteristics of the interferon-inducing yeast RNA-tilorone complex]. / Sravnitel'naia kharakteristika tsitotoksichnosti interferon-indutsiruiushchego kompleksa drozhzhevaia RNK-tiloron.

Cytotoxicity of the yeast RNA-tilorona molecular complex (MC) with interferonogenic properties and its influence on the DNA replicative synthesis were studied in experiments with human lymphocytes and 3 cell lines. It was shown that the MC doses of 25, 100 and 250 micrograms/ml were absolutely nontoxic for all the cell lines. The main parameters of the MC toxicity based on the cell viability were calculated. The parameters were found to correlate in the order of their magnitude with those relating to interferonogens of the polynucleotide nature. Within the dose ranges of 10 to 100 micrograms/ml the MC had a stimulating effect on replicative processes in the cells. It was concluded that the use of the MC as an inductor in large-scale manufacture of human and animal interferons of type 1 was promising.

[Study of anti-HIV activity of the yeast RNA-tilorone molecular complex]. / Izuchenie anti-VICh-aktivnosti molekuliarnogo kompleksa drozhzhevaia RNK-tiloron.

Anti-HIV activity of the molecular complex forming during interaction between yeast RNA and tilorone was studied in vitro on the models of acute and chronic infection. Addition of this agent to the cells infected with HIV-1/IIIB and HIV-1/BRU decreased the virus reproduction controlled by assessing the viability of cells, syncytium production, and accumulation of p24 antigen in culture medium. The authors hypothesize that the detected anti-HIV effect is due to its capacity to produce type I interferon and direct antiviral action.

[The depression of the reproduction of the human immunodeficiency virus by the use of Bogomolets antireticular cytotoxic serum]. / Pryhnichennia reproduktsiï virusu imunodefitsytu liudyny za dopomohoiu antyretykuliarnoï tsytotoksychnoï syrovatky Bohomol'tsia.

The action of the Bogomolets' antireticular cytotoxic serum (ACS) as a HIV-1 reproduction inhibitor was studied on the model of human lymphoblastoid cell line MT-4/BRU (acute infection). The HIV-1 reproduction inhibition was estimated according to cell protection level for virus cytopathic action and p24 antigen level in the cultural media. The both tests data on ACS usage in dilutions 1:160-1:640 prove that the virus inhibition effect which may be compared with anti-HIV action of the well-known agent, azidothymidine, was observed. At this dilutions range ACS is devoid of the cell toxicity. The conclusion about perspectivity of ACS usage in the AIDS complex therapy was drawn.

HIV-1 reverse transcriptase inhibitor design using artificial neural networks.

Artificial neural networks were used to analyze and predict the human immunodeficiency virus type 1 reverse transcriptase inhibitors. The training and control sets included 44 molecules (most of them are well-known substances such as AZT, dde, etc.). The activities of the molecules were taken from literature. Topological indices were calculated and used as molecular parameters. The four most informative parameters were chosen and applied to predict activities of both new and control molecules. We used a network pruning algorithm and network ensembles to obtain the final classifier. Increasing of neural network generalization of the new data was observed, when using the aforementioned methods. The prognosis of new molecules revealed one molecule as possibly very active. It was confirmed by further biological tests.

[The immunological manifestations and cytological characteristics of infection caused by the simian immunodeficiency virus (SIV) in rhesus monkeys]. / Immunologicheskie proiavleniia i tsitologicheskie osobennosti infektsii, vyzvannoi obez'ian'im virusom immunodefitsita (SIV) u makak rezus.

The results of immunological and morphological studies of Asian macaques (Macaca mulatta) infected by simian immunodeficiency virus (SIV) are summarized in this review of literature. This virus causes development of the immunodeficiency disease that closely resembles human AIDS. Immunological parameters (CD count, antibody response etc.) are described promoting prediction of progression of immunodeficiency in monkeys. The morphological features of injury of internal organs indicate that SIV-induced immunodeficiency is the multisystem disease.

[A clinical and experimental study of longatsef]. / Kliniko-éksperimental'noe izuchenie longatsefa.

Data are reported of the results of clinical trials of the therapeutic efficacy of longaceph--a drug of the new generation of cephalosporins with a long period of half-decay--in acute pneumonia complicating influenza in 42 patients. The sensitivity of 120 microbial strains to longaceph was also studied. It was established that cephalosporin possesses a high efficacy in diseases caused by gram-positive and gram-negative microorganisms. A high degree of sensitivity to longaceph was observed in pneumococci biogenous and Streptococcus viridans, Staphylococcus aureus and epidermidis, klebsiellae and escherichiae. A new property of longaceph was found, namely, its capacity to stimulate the formation of endogenous interferon.

[Polysaccharide--a stimulant of DNA reparative synthesis]. / Polisakharid--stimuliator reparativnogo sinteza DNK.

It is stated that regulation of the repair synthesis of DNA underlies the antimutagenic action of the polysaccharide isolated from bacteria. Protective effect of polysaccharides is also displayed.

[Kinetics of DNA reparative replication in the spleen cells of CBA- and C57BL/6-strain mice induced by urethane and and the influenza virus]. / Kinetika reparativnoi replikatsii DNK kletok selezenki myshei linii CBA i C57BL/6, inutsirovannoi uretanom i virusom grippa.

Different kinetics of DNA repair replication induced by urethan and influenza virus was detected in mice of varying genotypes. Inhibition of repair replication was detected in the lymphocytes of C57BL/6 mice, infected with influenza virus and treated with urethan. No inhibition of repair replication was noted in CBA mice which is characteristic of resistance to influenza virus. However, stimulation of repair replication by influenza virus was observed in these cells.

[Study of the effect of parotitis vaccine on DNA repair in human lymphocytes]. / Izuchenie vliianiia parotitnoi vaktsiny na reparativnyi sintez DNK vlimfotsitakh cheloveka.

The effect of parotitis vaccine virus (strain L-3) on the DNA repair synthesis induced by 4-nitroquinoline-1-oxide has been studied. The efficiency of the repair synthesis depends on individual properties of the human body, viral multiplicity and concentration of the mutagen. A two-fold increase in DNA repair synthesis was obtained after infection of cells with low viral multiplicity (0.001 HADU50 per cell) and using 2.5 x 10(-7) M concentration of the mutagen A ten-fold increase in mutagen concentration affecting the infected cells was accompanied by the inhibition of DNA repair synthesis. Lymphocytes from children studied 7 days after vaccination by the attenuated virus did not reveal any changes in DNA repair synthesis as compared with the cells from nonvaccinated children.

[Regulation of the excisional repair system in in vitro-cultured human cells by measles viruses depending on their attenuation]. / Reguliatsiia ékstsizionnoi sistemy reparatsii v kletkakh cheloveka, kul'tiviruemykh in vitro, virusami kori v zavisimosti ot ikh attenuatsii.

The effect of measles viruses (attenuated strain L-16 and virulent strain Edmonston) was studied in human cells (line L-41) according to the criteria of repair: excision of thymine dimers, repair replication of DNA and resynthesis of DNA breaks induced by UV-irradiation. Reproduction of attenuated measles virus in cells was accompanied with stimulation of excision of thymine dimers and repair replication of DNA in contradistinction to mild virus. This phenomenon depended on multiplicity of infection.