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Bairamukov VY, Kovalev RA, Ankudinov AV, Pantina RA, Fedorova ND, Bukatin AS, Grigoriev SV, Varfolomeeva EY. Alterations in the chromatin packaging, driven by transcriptional activity, revealed by AFM. Biochim Biophys Acta Gen Subj 2024; 1868:130568. [PMID: 38242181 DOI: 10.1016/j.bbagen.2024.130568] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Revised: 01/12/2024] [Accepted: 01/16/2024] [Indexed: 01/21/2024]
Abstract
BACKGROUND The gene expression differs in the nuclei of normal and malignant mammalian cells, and transcription is a critical initial step, which defines the difference. The mechanical properties of transcriptionally active chromatin are still poorly understood. Recently we have probed transcriptionally active chromatin of the nuclei subjected to mechanical stress, by Atomic Force Microscopy (AFM) [1]. Nonetheless, a systematic study of the phenomenon is needed. METHODS Nuclei were deformed and studied by AFM. Non-deformed nuclei were studied by fluorescence confocal microscopy. Their transcriptional activity was studied by RNA electrophoresis. RESULTS The malignant nuclei under the study were stable to deformation and assembled of 100-300 nm beads-like units, while normal cell nuclei were prone to deformation. The difference in stability to deformation of the nuclei correlated with DNA supercoiling, and transcription-depended units were responsive to supercoils breakage. The inhibitors of the topoisomerases I and II disrupted supercoiling and made the malignant nucleus prone to deformation. Cell nuclei treatment with histone deacetylase inhibitors (HDACIs) preserved the mechanical stability of deformed malignant nuclei and, at the same time, made it possible to observe chromatin decondensation up to 20-60 nm units. The AFM results were supplemented with confocal microscopy and RNA electrophoresis data. CONCLUSIONS Self-assembly of transcriptionally active chromatin and its decondensation, driven by DNA supercoiling-dependent rigidity, was visualized by AFM in the mechanically deformed nuclei. GENERAL SIGNIFICANCE We demonstrated that supercoiled DNA defines the transcription mechanics, and hypothesized the nuclear mechanics in vivo should depend on the chromatin architecture.
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Affiliation(s)
- V Yu Bairamukov
- Petersburg Nuclear Physics Institute Named by B.P. Konstantinov of NRC "Kurchatov Institute", 1, Orlova Roshcha, 188300 Gatchina, Russia.
| | - R A Kovalev
- Petersburg Nuclear Physics Institute Named by B.P. Konstantinov of NRC "Kurchatov Institute", 1, Orlova Roshcha, 188300 Gatchina, Russia
| | - A V Ankudinov
- The Ioffe Physical-Technical Institute of the Russian Academy of Sciences, 26, Politekhnicheskaya, 194021 Saint Petersburg, Russia
| | - R A Pantina
- Petersburg Nuclear Physics Institute Named by B.P. Konstantinov of NRC "Kurchatov Institute", 1, Orlova Roshcha, 188300 Gatchina, Russia
| | - N D Fedorova
- Petersburg Nuclear Physics Institute Named by B.P. Konstantinov of NRC "Kurchatov Institute", 1, Orlova Roshcha, 188300 Gatchina, Russia
| | - A S Bukatin
- Alferov Saint Petersburg National Research Academic University of the Russian Academy of Sciences, 8/3, Khlopina St., 194021 Saint Petersburg, Russia
| | - S V Grigoriev
- Petersburg Nuclear Physics Institute Named by B.P. Konstantinov of NRC "Kurchatov Institute", 1, Orlova Roshcha, 188300 Gatchina, Russia
| | - E Yu Varfolomeeva
- Petersburg Nuclear Physics Institute Named by B.P. Konstantinov of NRC "Kurchatov Institute", 1, Orlova Roshcha, 188300 Gatchina, Russia
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Kovalev RA, Fedorova ND, Pantina RA, Semenova EV, Filatov MV, Varfolomeeva EY. Stochasticity of p53 Protein Expression in Cells of Primary and Transferable Human Lines. Biophysics (Nagoya-shi) 2022. [DOI: 10.1134/s0006350922030101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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Iashina EG, Varfolomeeva EY, Pantina RA, Bairamukov VY, Kovalev RA, Fedorova ND, Pipich V, Radulescu A, Grigoriev SV. Bifractal structure of chromatin in rat lymphocyte nuclei. Phys Rev E 2021; 104:064409. [PMID: 35030913 DOI: 10.1103/physreve.104.064409] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Accepted: 11/29/2021] [Indexed: 11/07/2022]
Abstract
The small-angle neutron scattering (SANS) on the rat lymphocyte nuclei demonstrates the bifractal nature of the chromatin structural organization. The scattering intensity from rat lymphocyte nuclei is described by power law Q^{-D} with fractal dimension approximately 2.3 on smaller scales and 3 on larger scales. The crossover between two fractal structures is detected at momentum transfer near 10^{-1}nm^{-1}. The use of contrast variation (D_{2}O-H_{2}O) in SANS measurements reveals clear similarity in the structural organizations of nucleic acids (NA) and proteins. Both chromatin components show bifractal behavior with logarithmic fractal structure on the large scale and volume fractal with slightly smaller than 2.5 structure on the small scale. Scattering intensities from chromatin, protein component, and NA component demonstrate an extremely extensive range of logarithmic fractal behavior (from 10^{-3} to approximately 10^{-1}nm^{-1}). We compare the fractal arrangement of rat lymphocyte nuclei with that of chicken erythrocytes and the immortal HeLa cell line. We conclude that the bifractal nature of the chromatin arrangement is inherent in the nuclei of all these cells. The details of the fractal arrangement-its range and correlation/interaction between nuclear acids and proteins are specific for different cells and is related to their functionality.
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Affiliation(s)
- E G Iashina
- Petersburg Nuclear Physics Institute (PNPI), NRC Kurchatov Institute, Orlova roshcha 1, 188300, Gatchina, Russia.,Saint-Petersburg State University (SPSU), Ulyanovskaya str. 1, 198504, Saint-Petersburg, Russia
| | - E Yu Varfolomeeva
- Petersburg Nuclear Physics Institute (PNPI), NRC Kurchatov Institute, Orlova roshcha 1, 188300, Gatchina, Russia
| | - R A Pantina
- Petersburg Nuclear Physics Institute (PNPI), NRC Kurchatov Institute, Orlova roshcha 1, 188300, Gatchina, Russia
| | - V Yu Bairamukov
- Petersburg Nuclear Physics Institute (PNPI), NRC Kurchatov Institute, Orlova roshcha 1, 188300, Gatchina, Russia
| | - R A Kovalev
- Petersburg Nuclear Physics Institute (PNPI), NRC Kurchatov Institute, Orlova roshcha 1, 188300, Gatchina, Russia
| | - N D Fedorova
- Petersburg Nuclear Physics Institute (PNPI), NRC Kurchatov Institute, Orlova roshcha 1, 188300, Gatchina, Russia
| | - V Pipich
- Jülich Centre for Neutron Science (JCNS) at Heinz Maier-Leibnitz Zentrum (MLZ) Forschungszentrum Jülich GmbH, Lichtenbergstr. 1, D-85748 Garching, Germany
| | - A Radulescu
- Jülich Centre for Neutron Science (JCNS) at Heinz Maier-Leibnitz Zentrum (MLZ) Forschungszentrum Jülich GmbH, Lichtenbergstr. 1, D-85748 Garching, Germany
| | - S V Grigoriev
- Petersburg Nuclear Physics Institute (PNPI), NRC Kurchatov Institute, Orlova roshcha 1, 188300, Gatchina, Russia.,Saint-Petersburg State University (SPSU), Ulyanovskaya str. 1, 198504, Saint-Petersburg, Russia
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Grigoriev SV, Iashina EG, Wu B, Pipich V, Lang C, Radulescu A, Bairamukov VY, Filatov MV, Pantina RA, Varfolomeeva EY. Observation of nucleic acid and protein correlation in chromatin of HeLa nuclei using small-angle neutron scattering with D_{2}O-H_{2}O contrast variation. Phys Rev E 2021; 104:044404. [PMID: 34781557 DOI: 10.1103/physreve.104.044404] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Accepted: 08/30/2021] [Indexed: 01/06/2023]
Abstract
The small-angle neutron scattering (SANS) on HeLa nuclei demonstrates the bifractal nature of the chromatin structural organization. The border line between two fractal structures is detected as a crossover point at Q_{c}≈4×10^{-2}nm^{-1} in the momentum transfer dependence Q^{-D}. The use of contrast variation (D_{2}O-H_{2}O) in SANS measurements reveals clear similarity in the large scale structural organizations of nucleic acids (NA) and proteins. Both NA and protein structures have a mass fractal arrangement with the fractal dimension of D≈2.5 at scales smaller than 150 nm down to 20 nm. Both NA and proteins show a logarithmic fractal behavior with D≈3 at scales larger than 150 nm up to 6000 nm. The combined analysis of the SANS and atomic force microscopy data allows one to conclude that chromatin and its constitutes (DNA and proteins) are characterized as soft, densely packed, logarithmic fractals on the large scale and as rigid, loosely packed, mass fractals on the smaller scale. The comparison of the partial cross sections from NA and proteins with one from chromatin as a whole demonstrates spatial correlation of two chromatin's components in the range up to 900 nm. Thus chromatin in HeLa nuclei is built as the unified structure of the NA and proteins entwined through each other. Correlation between two components is lost upon scale increases toward 6000 nm. The structural features at the large scale, probably, provide nuclei with the flexibility and chromatin-free space to build supercorrelations on the distance of 10^{3} nm resembling cycle cell activity, such as an appearance of nucleoli and a DNA replication.
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Affiliation(s)
- S V Grigoriev
- Petersburg Nuclear Physics Institute named by B.P.Konstantinov of NRC Kurchatov Institute, Gatchina, St-Petersburg 188300, Russia.,Saint-Petersburg State University, Ulyanovskaya 1, Saint-Petersburg 198504, Russia
| | - E G Iashina
- Petersburg Nuclear Physics Institute named by B.P.Konstantinov of NRC Kurchatov Institute, Gatchina, St-Petersburg 188300, Russia.,Saint-Petersburg State University, Ulyanovskaya 1, Saint-Petersburg 198504, Russia
| | - B Wu
- Forschungszentrum Juelich, JCNS-4 at MLZ, Lichtenbergstr. 1, 85748 Garching, Germany
| | - V Pipich
- Forschungszentrum Juelich, JCNS-4 at MLZ, Lichtenbergstr. 1, 85748 Garching, Germany
| | - Ch Lang
- Forschungszentrum Juelich, JCNS-4 at MLZ, Lichtenbergstr. 1, 85748 Garching, Germany
| | - A Radulescu
- Forschungszentrum Juelich, JCNS-4 at MLZ, Lichtenbergstr. 1, 85748 Garching, Germany
| | - V Yu Bairamukov
- Petersburg Nuclear Physics Institute named by B.P.Konstantinov of NRC Kurchatov Institute, Gatchina, St-Petersburg 188300, Russia
| | - M V Filatov
- Petersburg Nuclear Physics Institute named by B.P.Konstantinov of NRC Kurchatov Institute, Gatchina, St-Petersburg 188300, Russia
| | - R A Pantina
- Petersburg Nuclear Physics Institute named by B.P.Konstantinov of NRC Kurchatov Institute, Gatchina, St-Petersburg 188300, Russia
| | - E Yu Varfolomeeva
- Petersburg Nuclear Physics Institute named by B.P.Konstantinov of NRC Kurchatov Institute, Gatchina, St-Petersburg 188300, Russia
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Grigoriev SV, Iashina EG, Bairamukov VY, Pipich V, Radulescu A, Filatov MV, Pantina RA, Varfolomeeva EY. Switch of fractal properties of DNA in chicken erythrocytes nuclei by mechanical stress. Phys Rev E 2020; 102:032415. [PMID: 33075965 DOI: 10.1103/physreve.102.032415] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Accepted: 09/13/2020] [Indexed: 11/07/2022]
Abstract
The small-angle neutron scattering (SANS) on the chicken erythrocyte nuclei demonstrates the bifractal nature of the chromatin structural organization. Use of the contrast variation (D_{2}O-H_{2}O) in SANS measurements reveals the differences in the DNA and protein arrangements inside the chromatin substance. It is the DNA that serves as a framework that constitutes the bifractal behavior showing the mass fractal properties with D=2.22 at a smaller scale and the logarithmic fractal behavior with D≈3 at a larger scale. The protein spatial organization shows the mass fractal properties with D≈2.34 throughout the whole nucleus. The borderline between two fractal levels can be significantly shifted toward smaller scales by centrifugation of the nuclei disposed on the dry substrate, since nuclei suffer from mechanical stress transforming them to a disklike shape. The height of this disk measured by atomic force microscopy (AFM) coincides closely with the fractal borderline, thus characterizing two types of the chromatin with the soft (at larger scale) and rigid (at smaller scale) properties. The combined SANS and AFM measurements demonstrate the stress induced switch of the DNA fractal properties from the rigid, but loosely packed, mass fractal to the soft, but densely packed, logarithmic fractal.
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Affiliation(s)
- S V Grigoriev
- Petersburg Nuclear Physics Institute, Gatchina, St-Petersburg, 188300, Russia.,Saint-Petersburg State University, Ulyanovskaya 1, Saint-Petersburg, 198504, Russia
| | - E G Iashina
- Petersburg Nuclear Physics Institute, Gatchina, St-Petersburg, 188300, Russia
| | - V Yu Bairamukov
- Petersburg Nuclear Physics Institute, Gatchina, St-Petersburg, 188300, Russia
| | - V Pipich
- Heinz Maier-Leibnitz Zentrum, Lichtenbergstraße 1, 85748 Garching bei München, Germany
| | - A Radulescu
- Heinz Maier-Leibnitz Zentrum, Lichtenbergstraße 1, 85748 Garching bei München, Germany
| | - M V Filatov
- Petersburg Nuclear Physics Institute, Gatchina, St-Petersburg, 188300, Russia
| | - R A Pantina
- Petersburg Nuclear Physics Institute, Gatchina, St-Petersburg, 188300, Russia
| | - E Yu Varfolomeeva
- Petersburg Nuclear Physics Institute, Gatchina, St-Petersburg, 188300, Russia
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Burdakov VS, Kovalev RA, Pantina RA, Varfolomeeva EY, Makarov EM, Filatov MV. Exosomes Transfer p53 between Cells and Can Suppress Growth and Proliferation of p53-Negative Cells. ACTA ACUST UNITED AC 2018. [DOI: 10.1134/s1990519x18010030] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Belyakova NV, Pantina RA, Kovalev RA, Filatov MV, Naryzhny SN. [Quaternary structures of human cytoplasmic and nuclear PCNA are the same]. Biomed Khim 2017; 63:356-360. [PMID: 28862608 DOI: 10.18097/pbmc20176304356] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Properties and mechanisms of PCNA (proliferating cell nuclear antigen) functions have been investigated for a long time and are studied in great detail. As follows from its name, most known PCNA functions (DNA replication, DNA repair, DNA recombination and others) are connected with cell proliferation and localization of this protein in nuclei. In addition, there is good reason to believe that PCNA also performs some functions in the cytoplasm. However, the possible role and mechanisms of PCNA action in the cytoplasm require careful study and clarification. Interestingly, such cells as neutrophils differ in that they are non-dividing on one hand and on the other hand contain a rather large amount of PCNA, which is localized only in the cytoplasm, that is, they are an ideal model for the study of cytoplasmic PCNA. Using cross-linkages with formaldehyde, we showed that this cytoplasmic PCNA is cross-linked in a similar way, that is, organized in the same way as the nuclear PCNA that is present in the proliferating cells. Previously, we showed that PCNA in such cells is organized into a dynamic complex of double trimer on the basis of the back-to-back principle (Naryzhny S.N. et al. (2005) J. Biol. Chem., 280, 13888). Apparently, such organization of this hub-protein allows it to better coordinate the processes taking place in the cytoplasm as well.
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Affiliation(s)
- N V Belyakova
- Petersburg Nuclear Physics Institute NRC Kurchatov Institute, Leningrad region (PNPI), Gatchina, Russia
| | - R A Pantina
- Petersburg Nuclear Physics Institute NRC Kurchatov Institute, Leningrad region (PNPI), Gatchina, Russia
| | - R A Kovalev
- Petersburg Nuclear Physics Institute NRC Kurchatov Institute, Leningrad region (PNPI), Gatchina, Russia
| | - M V Filatov
- Petersburg Nuclear Physics Institute NRC Kurchatov Institute, Leningrad region (PNPI), Gatchina, Russia
| | - S N Naryzhny
- Petersburg Nuclear Physics Institute NRC Kurchatov Institute, Leningrad region (PNPI), Gatchina, Russia
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Naryzhny SN, Ronzhina NL, Mainskova MA, Belyakova NV, Pantina RA, Filatov MV. Development of barcode and proteome profiling of glioblastoma. Biochem Moscow Suppl Ser B 2014. [DOI: 10.1134/s1990750814030111] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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Filatov MV, Landa SB, Pantina RA, Garmaĭ IP. [Investigation of exosomes secreted by different normal and malignant cells in vitro and in vivo]. Klin Lab Diagn 2010:35-43. [PMID: 21395053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Laser correlation spectroscopy, atomic force microscopy, and immunoaffinity chromatography were used to characterize exosomes produced by different human cells. The exosomes secreted into a culture medium by normal fibroblasts, dendritic cells, lymphocytes, as well as malignant cells obtained from tumors of various tissue origins. The similar investigations were made for exosomes detectable in plasma and cerebrospinal fluid. The dynamic light scattering technique has demonstrated that the exosomes from different sources are homogenous and similar in size of the order of 20 and 90 nm. The exceptional homogeneity of exosomes was confirmed by atomic force microscopy. The immunoaffinity method has shown that all the exosomes under study carry antigenic determinants recognizable by antibodies to the major histocompatibility complex of type 1 (HLA-ABC). A method is proposed for evidence-based detection of exosomes in various biological fluids. For this, dynamic light scattering detects 20- and 90-nm particles and whether they can be removed by immunoaffinity chromatography with HLA-ABC antibodies is checked.
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Lebedev DV, Filatov MV, Kuklin AI, Islamov AK, Stellbrink J, Pantina RA, Denisov YY, Toperverg BP, Isaev-Ivanov VV. Structural hierarchy of chromatin in chicken erythrocyte nuclei based on small-angle neutron scattering: Fractal nature of the large-scale chromatin organization. CRYSTALLOGR REP+ 2008. [DOI: 10.1134/s1063774508010136] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Shtam TA, Pantina RA, Varfolomeeva EI, Filatov MV. [Response to tamoxifen in estrogen receptor-positive cell line MCF-7 is independent of p53 expression]. Vopr Onkol 2007; 53:194-9. [PMID: 17663174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
The study was concerned with identification of predictive value of p53 expression on sensitivity to tamoxifen in breast cancer management. Estrogen receptor-positive cell line MCF-7 was used to establish p53 expression influence on the rate of cell proliferation after tamoxifen. The investigation demonstrated the absence of that effect when p53 was silenced.
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Ivanov AV, Bakhlanova IV, Pantina RA, Filatov MV. [Instability of plasmid DNA integrated into mammalian somatic cell genome]. Tsitologiia 2004; 46:740-7. [PMID: 15598021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/01/2023]
Abstract
The phenomenon of loosing exogenic DNA from the mammalian somatic cell genome is under investigation. It is found that foreign DNA incorporated into cell genome as a result of transfection by electrophoretion may be lost with the frequency from 1/100 up to 1/100 000 per cell division during cultivation. This effect is not dependent of the nature of cell line and vector DNA. It is actual for different cell lines: A23, human fibroblasts AG 11395, murine embryonic line F9, and for different plasmid vectors: p16, p.39, pATR4 and pcDNA3.1-Higr (WRN). Integration of pDNA into genome and the following loosing of this DNA is registered by selection markers G418 and hygromycin B resistance and gancyclovir sensibility. The presence of foreign DNA in the genome was controlled by PCR. It is found that true foreign DNA deletion from the genome takes place rather than gene expression changes. For closely linked plasmid genes deletion of both genes at once as well as loosing any one gene separately is shown. Thus, the phenomenon of selective deletion of exogenic DNA from genome has been demonstrated for different mammalian cells.
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Abstract
A phenomenon of spontaneous DNA instability displays itself as the low level of repair DNA synthesis that takes place during any cell cycle phases. However, there is a problem in detection of very low intensive repair DNA synthesis. This paper suggests two approaches to detect the spontaneous DNA instability. The first method involves a blockade of the DNA gaps sealing by a combination of inhibitors, hydroxyurea and arabinofuranosyl cytosine. An accumulation of single strand gaps leads to production of DNA double strand breaks and results to reproductive inactivation of cells. It was shown that registration of both these events by different methods (such as viscoelastometry of DNA, orthogonal pulse electrophoresis or comet assay for double strand breaks as well as effectiveness of colony growth for cell inactivation) may be used as suitable measure of the spontaneous DNA instability. The second approach bases on photolysis of bromodeoxyuridine incorporated into repair DNA patches during the spontaneous repair DNA synthesis. Long wave UV irradiation of cells containing bromodeoxyuridine labeled DNA stained with Hoechst 33342 causes their inactivation. Experimental results presented confirm that both methods actually detect the spontaneous DNA instability. It takes note of the spontaneous DNA instability varies for cells from different tissues and species and increases during aging.
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Affiliation(s)
- M V Filatov
- St. Petersburg Nuclear Physics Institute, Gatchina, Russian Federation.
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Tret'iakov AN, Pantina RA, Kaboev OK. [Fast DNA amplification in small ultrathin-wall microplates]. Bioorg Khim 1997; 23:526-8. [PMID: 9265475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
A new method was developed for fast DNA amplification by polymerase chain reaction in tiny ultrathin microplates formed directly on the thermocycler's thermoblock. The microplates are made from thin (40-60 microns) polypropylene film by the thermal vacuum-formation method. Due to the effective heat transfer to 10-15 microliters samples and a high velocity of heating and cooling of the thermoblock (up to 7 degrees C/s), the total duration of the DNA amplification (30 cycles) is only 15-30 min.
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Tret'iakov AN, Gel'fand VM, Pantina RA, Shevtsov SP, Bulat SA. [Amplification of DNA for 15-30 minutes in single-use pipette tips]. Mol Biol (Mosk) 1994; 28:665-669. [PMID: 8052258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Amplification of 200-1000-bp DNA fragments was performed in 15-30 min using a rapid thermal cycler based on the commercial instrument TC-1000-1 (IRLEN, St. Petersburg, Russia). Plastic pipette tips were used as thin walled, high surface to volume-ratio tubes, to increase the rate of heating (cooling) of 20 microliters samples, which allowed the time required for DNA amplification to be considerably reduced (5-10 times).
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Filatov MV, Pantina RA, Frolova LI. [For the reproductive death of a cell, damage to a single chromosome is sufficient]. Tsitologiia 1986; 28:1364-8. [PMID: 3824524] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The Chinese hamster cells V-79 were treated with BUdR during one cell cycle; after that the cells were grown in the medium without BUdR and were irradiated by longwave-UV-light at different time. The cell survival after photolysis was compared with the percentage of metaphase plates with different number of chromosomes containing BUdR. It is concluded that for cell inactivation the presence of only one destroyed chromosome (or its part) is enough.
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