Showing papers by "Vladimir S. Prassolov published in 2011"

Sensitivity of acute myeloid leukemia Kasumi-1 cells to binase toxic action depends on the expression of KIT and АML1-ETO oncogenes

Abstract: Some RNases selectively attack malignant cells, triggering an apoptotic response, and therefore are considered as alternative chemotherapeutic drugs. Here we studied the effects of Bacillus intermedius RNase (binase) on murine myeloid progenitor cells FDC-P1; transduced FDC-P1 cells ectopically expressing mutated human KIT N822K oncogene and/or human AML1-ETO oncogene; and human leukemia Kasumi-1 cells expressing both of these oncogenes. Expression of both KIT and AML1-ETO oncogenes makes FDC-P1 cells sensitive to the toxic effects of binase. Kasumi-1 cells were the most responsive to the toxic actions of binase among the cell lines used in this work with an IC50 value of 0.56 µM. Either blocking the functional activity of the KIT protein with imatinib or knocking-down oncogene expression using lentiviral vectors producing shRNA against AML1-ETO or KIT eliminated the sensitivity of Kasumi-1 cells to binase toxic action and promoted their survival, even in the absence of KIT-dependent proliferation and ant...

Screening of Potential HIV-1 Inhibitors/Replication Blockers Using Secure Lentiviral in Vitro System.

Abstract: The development and usage of safe cell systems for testing agents which possess anti-HIV activity is a very important factor in the design of new drugs. We have described in detail a system we designed that is based on lentiviral vectors (Prokofjeva et. al., Antiviral Therapy, in print) for swift and completely safe screening of potential HIV-1 replication inhibitors. The system enables one to test the efficiency of the inhibitory activity of compounds whose action is directed towards either wild-type HIV-1 reverse transcriptase or integrase, or mutant enzymes corresponding to the drug-resistant virus form. Testing results of a number of already known drugs, which correlate well with published data as well as data on newly synthesized compounds, were obtained. Application of this system substantially broadens the possibilities of preclinical anti-HIV drugs testing. KEYWORDS HIV; lentiviral vectors; pseudo-HIV-1 particles; nucleoside reverse transcriptase inhibitors; non- nucleoside reverse transcriptase inhibitors; integrase inhibitors. ABBREVIATIONS HIV - human immunodeficiency virus; RT - reverse transcriptase; VSV - vesicular stomatitis virus; eGFP - enhanced green fluorescent protein; AZT - 3-azido-3- deoxythymidine; IC 50 - half maximal (50%) inhibitory concentration (IC) of a substance.

Novel Biomaterial for NCT—"Rigid" Particles of (DNA-Gadolinium) Liquid-Crystalline Dispersions

Abstract: The formation and physico-chemical properties of biomaterial, based on double-stranded (ds) DNA molecules and bearing high concentration of gadolinium, is described. This “rigid” biomaterial demonstrate a few unique properties: (i) the ds DNA molecules forming complexes with gadolinium are fixed in the spatial structure of “rigid” particles, (ii) an abnormal negative band in the circular dichroism spectrum permits to follow the formation of this biomaterial; (iii) local concentration gadolinium in the content of biomaterial can reach 40%. These properties show that we are dealing with a novel type of biomaterial strongly enriched by gadolinium. This opens a gateway for practical application of this biomaterial for neutron-capture reactions. A first attempt to apply this material for neutron-capture reaction in combination with neutron generator of thermal neutron flux was performed. Positive result obtained at destruction of CHO cells allows one to state that the advantages of this biomaterial are a simple manipulation with it, a possibility to adjust its gadolinium content, long-term stability of its physico-chemical properties, as well as a reduced cost of neutron-capture experiment.

Coordinated interaction of multifunctional members of the p53 family determines many key processes in multicellular organisms

Abstract: For the first time, p53 was found in complex with the viral large T-antigen in cells transformed with the small DNA virus SV40. p53 cDNA was cloned in the early 1980s, and the full-length p53 gene was cloned soon afterwards. The p53 family is comprised of three genes—TP53, TP63, and TP73—each of which is expressed as a set of structurally and functionally different isoforms. All of them intensely interact with each other, forming a united functional network of proteins. The review discusses the evolution of the p53 family and the significance of all its members in embryo development, reproduction, regeneration, regulation of aging and lifespan, and defense against cancer. Special attention is paid to the role of poorly studied members of the p53 family, p63 and p73, in carcinogenesis and tumor progression. Different isoforms of these proteins might exert opposite effects on these processes.

A new bidirectional promoter from the human genome

Abstract: Both human and other mammalian genomes contain a number of closely linked gene pairs transcribed in opposite directions. Bioinformatic analysis suggests that up to 10% of human genes are arranged in this way. This work reports cloning of a human genome fragment that separates two head-to-head oriented genes located at 2p13.1 and encoding hypothetical proteins with unknown functions: CCDC (Coiled Coil Domain Containing) 142 and TTC (TetraTricopeptide repeat Containing) 31. The intergenic region CCDC142-TTC31 overlaps with a CpG island and contains a number of potential binding sites for transcription factors. This fragment functions as a bidirectional promoter in the system of luciferase reporter gene expression upon transfection of human embryonic kidney (HEK293) cells. Vectors containing oppositely oriented genes of two fluorescent proteins: green (EGFP) and red (DsRed2), separated by a fragment of the CCDC142-TTC31 intergenic region, were constructed. Transfection of HEK293 cells with these vectors resulted in simultaneous expression of both fluorescent proteins. The promoter activity was also determined for truncated versions of the intergenic region. The minimal promoter fragment contained Inr, BRE, and DPE elements characteristic for TATA-less promoters. Thus, a novel bidirectional promoter was cloned from the human genome; it can be used for simultaneous constitutive expression of two different genes in human cells.

Characterization of a new splicing mutation in the steroid 21-hydroxylase gene

Abstract: We identified a novel mutation in the CYP21A2 gene, a C to G substitution in the 7-position of the intron 2 acceptor splice site (c.290-7C>G), which causes a steroid 21-hydroxylase deficiency. The effect of the mutation on splicing was checked in the system of CYP21A minigene expression in cultured mammalian cells. The mutation impairs the use of the intron 2 acceptor splice site, resulting in intron retention in mRNA.