1
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McGregor LA, Zhu B, Goetz AM, Sczepanski JT. Thymine DNA Glycosylase is an RNA-Binding Protein with High Selectivity for G-Rich Sequences. J Biol Chem 2023; 299:104590. [PMID: 36889585 PMCID: PMC10124917 DOI: 10.1016/j.jbc.2023.104590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Revised: 02/17/2023] [Accepted: 02/27/2023] [Indexed: 03/08/2023] Open
Abstract
Thymine DNA glycosylase (TDG) is a multifaceted enzyme involved in several critical biological pathways, including transcriptional activation, DNA demethylation, and DNA repair. Recent studies have established regulatory relationships between TDG and RNA, but the molecular interactions underlying these relationships is poorly understood. Herein, we now demonstrate that TDG binds directly to RNA with nanomolar affinity. Using synthetic oligonucleotides of defined length and sequence, we show that TDG has a strong preference for binding G-rich sequences in single-stranded RNA but binds weakly to single-stranded DNA and duplex RNA. TDG also binds tightly to endogenous RNA sequences. Studies with truncated proteins indicate that TDG binds RNA primarily through its structured catalytic domain and that its disordered C-terminal domain plays a key role in regulating TDG's affinity and selectivity for RNA. Finally, we show that RNA competes with DNA for binding to TDG, resulting in inhibition of TDG-mediated excision in the presence of RNA. Together, this work provides support for and insights into a mechanism wherein TDG-mediated processes (e.g., DNA demethylation) are regulated through the direct interactions of TDG with RNA.
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Affiliation(s)
- Lauren A McGregor
- Department of Chemistry, Texas A&M University, College Station, Texas, 77843, USA
| | - Baiyu Zhu
- Department of Chemistry, Texas A&M University, College Station, Texas, 77843, USA
| | - Allison M Goetz
- Department of Chemistry, Texas A&M University, College Station, Texas, 77843, USA
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2
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Andres AE, Mariano A, Rane D, Peterson BR. Quantification of Engagement of Microtubules by Small Molecules in Living Cells by Flow Cytometry. ACS BIO & MED CHEM AU 2022; 2:529-537. [PMID: 36281300 PMCID: PMC9585582 DOI: 10.1021/acsbiomedchemau.2c00031] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Revised: 07/25/2022] [Accepted: 07/27/2022] [Indexed: 11/29/2022]
Abstract
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Drugs such as paclitaxel (Taxol) that bind microtubules
are widely
used for the treatment of cancer. Measurements of the affinity and
selectivity of these compounds for their targets are largely based
on studies of purified proteins, and only a few quantitative methods
for the analysis of interactions of small molecules with microtubules
in living cells have been reported. We describe here a novel method
for rapidly quantifying the affinities of compounds that bind polymerized
tubulin in living HeLa cells. This method uses the fluorescent molecular
probe Pacific Blue-GABA-Taxol in conjunction with verapamil to block
cellular efflux. Under physiologically relevant conditions of 37 °C,
this combination allowed quantification of equilibrium saturation
binding of this probe to cellular microtubules (Kd = 1.7 μM) using flow cytometry. Competitive binding
of the microtubule stabilizers paclitaxel (cellular Ki = 22 nM), docetaxel (cellular Ki = 16 nM), cabazitaxel (cellular Ki = 6 nM), and ixabepilone (cellular Ki = 10 nM) revealed intracellular affinities for microtubules that
closely matched previously reported biochemical affinities. By including
a cooperativity factor (α) for curve fitting of allosteric modulators,
this probe also allowed quantification of binding (Kb) of the microtubule destabilizers colchicine (Kb = 80 nM, α = 0.08), vinblastine (Kb = 7 nM, α = 0.18), and maytansine (Kb = 3 nM, α = 0.21). Screening of this
assay against 1008 NCI diversity compounds identified NSC 93427 as
a novel microtubule destabilizer (Kb =
485 nM, α = 0.02), illustrating the potential of this approach
for drug discovery.
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Affiliation(s)
- Angelo E. Andres
- Division of Medicinal Chemistry and Pharmacognosy, The Ohio State University, Columbus, Ohio 43210, United States
| | - Andres Mariano
- Division of Medicinal Chemistry and Pharmacognosy, The Ohio State University, Columbus, Ohio 43210, United States
| | - Digamber Rane
- Division of Medicinal Chemistry and Pharmacognosy, The Ohio State University, Columbus, Ohio 43210, United States
| | - Blake R. Peterson
- Division of Medicinal Chemistry and Pharmacognosy, The Ohio State University, Columbus, Ohio 43210, United States
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3
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Aponte-Serrano JO, Weaver JJA, Sego TJ, Glazier JA, Shoemaker JE. Multicellular spatial model of RNA virus replication and interferon responses reveals factors controlling plaque growth dynamics. PLoS Comput Biol 2021; 17:e1008874. [PMID: 34695114 PMCID: PMC8608315 DOI: 10.1371/journal.pcbi.1008874] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 11/22/2021] [Accepted: 09/27/2021] [Indexed: 02/07/2023] Open
Abstract
Respiratory viruses present major public health challenges, as evidenced by the 1918 Spanish Flu, the 1957 H2N2, 1968 H3N2, and 2009 H1N1 influenza pandemics, and the ongoing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic. Severe RNA virus respiratory infections often correlate with high viral load and excessive inflammation. Understanding the dynamics of the innate immune response and its manifestations at the cell and tissue levels is vital to understanding the mechanisms of immunopathology and to developing strain-independent treatments. Here, we present a novel spatialized multicellular computational model of RNA virus infection and the type-I interferon-mediated antiviral response that it induces within lung epithelial cells. The model is built using the CompuCell3D multicellular simulation environment and is parameterized using data from influenza virus-infected cell cultures. Consistent with experimental observations, it exhibits either linear radial growth of viral plaques or arrested plaque growth depending on the local concentration of type I interferons. The model suggests that modifying the activity of signaling molecules in the JAK/STAT pathway or altering the ratio of the diffusion lengths of interferon and virus in the cell culture could lead to plaque growth arrest. The dependence of plaque growth arrest on diffusion lengths highlights the importance of developing validated spatial models of cytokine signaling and the need for in vitro measurement of these diffusion coefficients. Sensitivity analyses under conditions leading to continuous or arrested plaque growth found that plaque growth is more sensitive to variations of most parameters and more likely to have identifiable model parameters when conditions lead to plaque arrest. This result suggests that cytokine assay measurements may be most informative under conditions leading to arrested plaque growth. The model is easy to extend to include SARS-CoV-2-specific mechanisms or to use as a component in models linking epithelial cell signaling to systemic immune models.
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Affiliation(s)
- Josua O. Aponte-Serrano
- Department of Intelligent Systems Engineering, Indiana University, Bloomington, Indiana, United States of America
- Biocomplexity Institute, Indiana University, Bloomington, Indiana, United States of America
| | - Jordan J. A. Weaver
- Department of Chemical & Petroleum Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - T. J. Sego
- Department of Intelligent Systems Engineering, Indiana University, Bloomington, Indiana, United States of America
- Biocomplexity Institute, Indiana University, Bloomington, Indiana, United States of America
| | - James A. Glazier
- Department of Intelligent Systems Engineering, Indiana University, Bloomington, Indiana, United States of America
- Biocomplexity Institute, Indiana University, Bloomington, Indiana, United States of America
| | - Jason E. Shoemaker
- Department of Chemical & Petroleum Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- Department of Computational and Systems Biology, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
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4
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A large-scale nanoscopy and biochemistry analysis of postsynaptic dendritic spines. Nat Neurosci 2021; 24:1151-1162. [PMID: 34168338 DOI: 10.1038/s41593-021-00874-w] [Citation(s) in RCA: 60] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2020] [Accepted: 05/13/2021] [Indexed: 02/05/2023]
Abstract
Dendritic spines, the postsynaptic compartments of excitatory neurotransmission, have different shapes classified from 'stubby' to 'mushroom-like'. Whereas mushroom spines are essential for adult brain function, stubby spines disappear during brain maturation. It is still unclear whether and how they differ in protein composition. To address this, we combined electron microscopy and quantitative biochemistry with super-resolution microscopy to annotate more than 47,000 spines for more than 100 synaptic targets. Surprisingly, mushroom and stubby spines have similar average protein copy numbers and topologies. However, an analysis of the correlation of each protein to the postsynaptic density mass, used as a marker of synaptic strength, showed substantially more significant results for the mushroom spines. Secretion and trafficking proteins correlated particularly poorly to the strength of stubby spines. This suggests that stubby spines are less likely to adequately respond to dynamic changes in synaptic transmission than mushroom spines, which possibly explains their loss during brain maturation.
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5
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Gregg RW, Shabnam F, Shoemaker JE. Agent-based modeling reveals benefits of heterogeneous and stochastic cell populations during cGAS-mediated IFNβ production. Bioinformatics 2021; 37:1428-1434. [PMID: 33196784 DOI: 10.1093/bioinformatics/btaa969] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 10/13/2020] [Accepted: 11/04/2020] [Indexed: 01/25/2023] Open
Abstract
MOTIVATION The cGAS pathway is a component of the innate immune system responsible for the detection of pathogenic DNA and upregulation of interferon beta (IFNβ). Experimental evidence shows that IFNβ signaling occurs in highly heterogeneous cells and is stochastic in nature; however, the benefits of these attributes remain unclear. To investigate how stochasticity and heterogeneity affect IFNβ production, an agent-based model is developed to simulate both DNA transfection and viral infection. RESULTS We show that heterogeneity can enhance IFNβ responses during infection. Furthermore, by varying the degree of IFNβ stochasticity, we find that only a percentage of cells (20-30%) need to respond during infection. Going beyond this range provides no additional protection against cell death or reduction of viral load. Overall, these simulations suggest that heterogeneity and stochasticity are important for moderating immune potency while minimizing cell death during infection. AVAILABILITY AND IMPLEMENTATION Model repository is available at: https://github.com/ImmuSystems-Lab/AgentBasedModel-cGASPathway. SUPPLEMENTARY INFORMATION Supplementary data are available at Bioinformatics online.
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Affiliation(s)
- Robert W Gregg
- Department of Chemical and Petroleum Engineering, 15260, Pittsburgh, PA 15260, USA
| | - Fathima Shabnam
- Department of Chemical and Petroleum Engineering, 15260, Pittsburgh, PA 15260, USA
| | - Jason E Shoemaker
- Department of Chemical and Petroleum Engineering, 15260, Pittsburgh, PA 15260, USA.,McGowan Institute for Regenerative Medicine, 15219, Pittsburgh, PA 15260, USA.,Department of Computational and Systems Biology, University of Pittsburgh, Pittsburgh, PA 15260, USA
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6
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Ghaemi Z, Peterson JR, Gruebele M, Luthey-Schulten Z. An in-silico human cell model reveals the influence of spatial organization on RNA splicing. PLoS Comput Biol 2020; 16:e1007717. [PMID: 32210422 PMCID: PMC7094823 DOI: 10.1371/journal.pcbi.1007717] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Accepted: 02/06/2020] [Indexed: 01/12/2023] Open
Abstract
Spatial organization is a characteristic of all cells, achieved in eukaryotic cells by utilizing both membrane-bound and membrane-less organelles. One of the key processes in eukaryotes is RNA splicing, which readies mRNA for translation. This complex and highly dynamical chemical process involves assembly and disassembly of many molecules in multiple cellular compartments and their transport among compartments. Our goal is to model the effect of spatial organization of membrane-less organelles (specifically nuclear speckles) and of organelle heterogeneity on splicing particle biogenesis in mammalian cells. Based on multiple sources of complementary experimental data, we constructed a spatial model of a HeLa cell to capture intracellular crowding effects. We then developed chemical reaction networks to describe the formation of RNA splicing machinery complexes and splicing processes within nuclear speckles (specific type of non-membrane-bound organelles). We incorporated these networks into our spatially-resolved human cell model and performed stochastic simulations for up to 15 minutes of biological time, the longest thus far for a eukaryotic cell. We find that an increase (decrease) in the number of nuclear pore complexes increases (decreases) the number of assembled splicing particles; and that compartmentalization is critical for the yield of correctly-assembled particles. We also show that a slight increase of splicing particle localization into nuclear speckles leads to a disproportionate enhancement of mRNA splicing and a reduction in the noise of generated mRNA. Our model also predicts that the distance between genes and speckles has a considerable effect on the mRNA production rate, with genes located closer to speckles producing mRNA at higher levels, emphasizing the importance of genome organization around speckles. The HeLa cell model, including organelles and sub-compartments, provides a flexible foundation to study other cellular processes that are strongly modulated by spatiotemporal heterogeneity.
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Affiliation(s)
- Zhaleh Ghaemi
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| | - Joseph R. Peterson
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| | - Martin Gruebele
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
- Department of Physics, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| | - Zaida Luthey-Schulten
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
- Department of Physics, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
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7
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Parsons TK, Pratt RN, Tang L, Wu Y. An active and selective molecular mechanism mediating the uptake of sex steroids by prostate cancer cells. Mol Cell Endocrinol 2018; 477:121-131. [PMID: 29928927 DOI: 10.1016/j.mce.2018.06.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Revised: 05/31/2018] [Accepted: 06/16/2018] [Indexed: 12/21/2022]
Abstract
Steroid hormones play important roles in normal physiological functions and diseases. Sex steroids hormones are important in the biology and treatment of sex hormone-related cancer such as prostate cancer and breast cancer. Cells may take up steroids using multiple mechanisms. The conventionally accepted hypothesis that steroids cross cell membrane through passive diffusion has not been tested rigorously. Experimental data suggested that cells may take up sex steroid using an active uptake mechanism. 3H-testosterone uptake by prostate cancer cells showed typical transporter-mediated uptake kinetic. Cells retained testosterone taken up from the medium. The uptake of testosterone was selective for certain steroid hormones but not others. Data also indicated that the active and selective uptake mechanism resided in cholesterol-rich membrane domains, and may involve ATP and membrane transporters. In summary, the present study provided strong evidence to support the existence of an active and selective molecular mechanism for sex steroid uptake.
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Affiliation(s)
- Todd K Parsons
- Department of Urology, Roswell Park Comprehensive Cancer Center, Elm and Carlton Streets, Buffalo, NY, 14263, USA
| | - Rachel N Pratt
- Department of Cancer Prevention and Control, Roswell Park Comprehensive Cancer Center, Elm and Carlton Streets, Buffalo, NY, 14263, USA
| | - Li Tang
- Department of Cancer Prevention and Control, Roswell Park Comprehensive Cancer Center, Elm and Carlton Streets, Buffalo, NY, 14263, USA
| | - Yue Wu
- Department of Urology, Roswell Park Comprehensive Cancer Center, Elm and Carlton Streets, Buffalo, NY, 14263, USA.
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8
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Jiang X, Chen J, Bajić A, Zhang C, Song X, Carroll SL, Cai ZL, Tang M, Xue M, Cheng N, Schaaf CP, Li F, MacKenzie KR, Ferreon ACM, Xia F, Wang MC, Maletić-Savatić M, Wang J. Quantitative real-time imaging of glutathione. Nat Commun 2017; 8:16087. [PMID: 28703127 PMCID: PMC5511354 DOI: 10.1038/ncomms16087] [Citation(s) in RCA: 166] [Impact Index Per Article: 23.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Accepted: 05/23/2017] [Indexed: 02/06/2023] Open
Abstract
Glutathione plays many important roles in biological processes; however, the dynamic changes of glutathione concentrations in living cells remain largely unknown. Here, we report a reversible reaction-based fluorescent probe—designated as RealThiol (RT)—that can quantitatively monitor the real-time glutathione dynamics in living cells. Using RT, we observe enhanced antioxidant capability of activated neurons and dynamic glutathione changes during ferroptosis. RT is thus a versatile tool that can be used for both confocal microscopy and flow cytometry based high-throughput quantification of glutathione levels in single cells. We envision that this new glutathione probe will enable opportunities to study glutathione dynamics and transportation and expand our understanding of the physiological and pathological roles of glutathione in living cells. Fluorescent sensors for small biomolecules are needed to shed insight into real-time cellular processes. Here the authors develop RealThiol, a sensor that can quantitatively monitor glutathione dynamics in living cells, and measure increased antioxidant capability of activated neurons and glutathione changes during ferroptosis.
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Affiliation(s)
- Xiqian Jiang
- Department of Pharmacology and Chemical Biology, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Jianwei Chen
- Department of Pharmacology and Chemical Biology, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Aleksandar Bajić
- Department of Pediatrics, Baylor College of Medicine, Houston, Texas 77030, USA.,Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, Texas 77030, USA
| | - Chengwei Zhang
- Department of Pharmacology and Chemical Biology, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Xianzhou Song
- Department of Pharmacology and Chemical Biology, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Shaina L Carroll
- Department of Pharmacology and Chemical Biology, Baylor College of Medicine, Houston, Texas 77030, USA.,Department of Chemistry, Rice University, Houston, Texas 77030, USA
| | - Zhao-Lin Cai
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas 77030, USA.,The Cain Foundation Laboratories, Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, Texas 77030, USA
| | - Meiling Tang
- Department of Pharmacology and Chemical Biology, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Mingshan Xue
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas 77030, USA.,The Cain Foundation Laboratories, Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, Texas 77030, USA.,Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Ninghui Cheng
- Department of Pediatrics, Baylor College of Medicine, Houston, Texas 77030, USA.,USDA/ARS Children Nutrition Research Center, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Christian P Schaaf
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, Texas 77030, USA.,Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Feng Li
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas 77030, USA.,Center for Drug Discovery, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Kevin R MacKenzie
- Center for Drug Discovery, Baylor College of Medicine, Houston, Texas 77030, USA.,Department of Pathology, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Allan Chris M Ferreon
- Department of Pharmacology and Chemical Biology, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Fan Xia
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Meng C Wang
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA.,Huffington Center on Aging, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Mirjana Maletić-Savatić
- Department of Pediatrics, Baylor College of Medicine, Houston, Texas 77030, USA.,Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, Texas 77030, USA.,Center for Drug Discovery, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Jin Wang
- Department of Pharmacology and Chemical Biology, Baylor College of Medicine, Houston, Texas 77030, USA.,Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas 77030, USA.,Center for Drug Discovery, Baylor College of Medicine, Houston, Texas 77030, USA
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9
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Feliu N, Sun X, Alvarez Puebla RA, Parak WJ. Quantitative Particle-Cell Interaction: Some Basic Physicochemical Pitfalls. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:6639-6646. [PMID: 28379704 DOI: 10.1021/acs.langmuir.6b04629] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
There are numerous reports about particle-cell interaction studies in the literature. Many of those are performed in two-dimensional cell cultures. While the interpretation of such studies seems trivial at first sight, in fact for quantitative analysis some basic physical and physicochemical bases need to be considered. This starts with the dispersion of the particles, for which gravity, Brownian motion, and interparticle interactions need to be considered. The respective strength of these interactions determines whether the particles will sediment, are dispersed, or are agglomerated. This in turn largely influences their interaction with cells. While in the case of well-dispersed particles only a fraction of them will come into contact with cells in a two-dimensional culture, (agglomeration-induced) sedimentation drives the particles toward the cell surface, resulting in enhanced uptake.
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Affiliation(s)
- Neus Feliu
- Fachbereich Physik, Philipps Universität Marburg , Marburg, Germany
- Department of Laboratory Medicine (LABMED), Karolinska Institutet , Stockholm, Sweden
- Medcom Advance S.A., Barcelona, Spain
| | - Xing Sun
- Fachbereich Physik, Philipps Universität Marburg , Marburg, Germany
| | - Ramon A Alvarez Puebla
- Departamento de Química Física e Inorgánica and Emas, Universitat Rovira i Virgili , Tarragona, Spain
- ICREA, Barcelona, Spain
| | - Wolfgang J Parak
- Fachbereich Physik, Philipps Universität Marburg , Marburg, Germany
- Institute of Nano Biomedicine and Engineering, Key Laboratory for Thin Film and Microfabrication Technology of the Ministry of Education, Department of Instrument Science and Engineering, School of Electronic Information and Electrical Engineering, Shanghai Jiao Tong University , Shanghai, China
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10
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Oleksiewicz MB, Thorup I, Nielsen HS, Andersen HV, Hegelund AC, Iversen L, Guldberg TS, Brinck PR, Sjogren I, Thinggaard UK, Jørgensen L, Jensen MB. Generalized Cellular Hypertrophy is Induced by a Dual-Acting PPAR Agonist in Rat Urinary Bladder Urothelium In Vivo. Toxicol Pathol 2016; 33:552-60. [PMID: 16076770 DOI: 10.1080/01926230500214657] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Some developmental dual-acting PPARα/γ agonists, such as ragaglitazar, have shown carcinogenic effects in the rodent urinary bladder urothelium after months-years of dosing. We examined early (precancerous) changes in the bladder urothelium of rats orally dosed with ragaglitazar, using a newly developed flow cytometric method. Following 3 weeks of oral ragaglitazar dosing, increases in physical size occurred in a generalized fashion in rat bladder urothelial cells, determined by flow cytometry. Protein/DNA measurements confirmed increased protein content of urothelial cells in the bladder, and hypertrophy was observed in the kidney pelvis urothelium by histopathology. In animals exhibiting urothelial hypertrophy, no cell cycle changes were detected in parallel samples of bladder urothelium. Interestingly, urothelial cells from normal rats were found to constitute a unique type of noncycling population, with high G2/M fractions. In summary, our findings showed that in the urothelium of ragaglitazar-treated animals, hypertrophy (increased size and protein content per cell) was an early change, that affected the whole bladder urothelial cell population. The urothelial hypertrophy was primary, i.e., occurred in the absence of similarly pronounced changes in cell cycle distributions. To our knowledge, this is the first report of a direct hypertrophic effect of a PPAR agonist. Urothelial hypertrophy might be a relevant early biological endpoint in mechanistic studies regarding the bladder-carcinogenic effect of PPAR agonists.
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Affiliation(s)
- Martin B Oleksiewicz
- Novo Nordisk A/S, Novo Nordisk Park, Department of Virology and Molecular Toxicology, Maalov, Denmark.
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11
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Virant-Klun I, Leicht S, Hughes C, Krijgsveld J. Identification of Maturation-Specific Proteins by Single-Cell Proteomics of Human Oocytes. Mol Cell Proteomics 2016; 15:2616-27. [PMID: 27215607 DOI: 10.1074/mcp.m115.056887] [Citation(s) in RCA: 143] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Indexed: 12/25/2022] Open
Abstract
Oocytes undergo a range of complex processes via oogenesis, maturation, fertilization, and early embryonic development, eventually giving rise to a fully functioning organism. To understand proteome composition and diversity during maturation of human oocytes, here we have addressed crucial aspects of oocyte collection and proteome analysis, resulting in the first proteome and secretome maps of human oocytes. Starting from 100 oocytes collected via a novel serum-free hanging drop culture system, we identified 2,154 proteins, whose function indicate that oocytes are largely resting cells with a proteome that is tailored for homeostasis, cellular attachment, and interaction with its environment via secretory factors. In addition, we have identified 158 oocyte-enriched proteins (such as ECAT1, PIWIL3, NLRP7)(1) not observed in high-coverage proteomics studies of other human cell lines or tissues. Exploiting SP3, a novel technology for proteomic sample preparation using magnetic beads, we scaled down proteome analysis to single cells. Despite the low protein content of only ∼100 ng per cell, we consistently identified ∼450 proteins from individual oocytes. When comparing individual oocytes at the germinal vesicle (GV) and metaphase II (MII) stage, we found that the Tudor and KH domain-containing protein (TDRKH) is preferentially expressed in immature oocytes, while Wee2, PCNA, and DNMT1 were enriched in mature cells, collectively indicating that maintenance of genome integrity is crucial during oocyte maturation. This study demonstrates that an innovative proteomics workflow facilitates analysis of single human oocytes to investigate human oocyte biology and preimplantation development. The approach presented here paves the way for quantitative proteomics in other quantity-limited tissues and cell types. Data associated with this study are available via ProteomeXchange with identifier PXD004142.
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Affiliation(s)
- Irma Virant-Klun
- From the ‡Reproductive Unit, Department of Obstetrics and Gynecology, University Medical Centre Ljubljana, Slajmerjeva 3, 1000 Ljubljana, Slovenia
| | - Stefan Leicht
- §European Molecular Biology Laboratory (EMBL), Meyerhofstrasse 1, 69117 Heidelberg, Germany
| | - Christopher Hughes
- ¶British Columbia Cancer Research Agency, 675 West 10th Avenue, Vancouver, Canada
| | - Jeroen Krijgsveld
- §European Molecular Biology Laboratory (EMBL), Meyerhofstrasse 1, 69117 Heidelberg, Germany; ‖German Cancer Research Center and Heidelberg University, Im Neuenheimer Feld 581, 69120, Heidelberg, Germany
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12
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Darzynkiewicz Z, Zhao H, Zhang S, Marietta YL, Ernest YL, Zhang Z. Initiation and termination of DNA replication during S phase in relation to cyclins D1, E and A, p21WAF1, Cdt1 and the p12 subunit of DNA polymerase δ revealed in individual cells by cytometry. Oncotarget 2015; 6:11735-50. [PMID: 26059433 PMCID: PMC4494901 DOI: 10.18632/oncotarget.4149] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2015] [Accepted: 05/03/2015] [Indexed: 12/18/2022] Open
Abstract
During our recent studies on mechanism of the regulation of human DNA polymerase δ in preparation for DNA replication or repair, multiparameter imaging cytometry as exemplified by laser scanning cytometry (LSC) has been used to assess changes in expression of the following nuclear proteins associated with initiation of DNA replication: cyclin A, PCNA, Ki-67, p21(WAF1), DNA replication factor Cdt1 and the smallest subunit of DNA polymerase δ, p12. In the present review, rather than focusing on Pol δ, we emphasize the application of LSC in these studies and outline possibilities offered by the concurrent differential analysis of DNA replication in conjunction with expression of the nuclear proteins. A more extensive analysis of the data on a correlation between rates of EdU incorporation, likely reporting DNA replication, and expression of these proteins, is presently provided. New data, specifically on the expression of cyclin D1 and cyclin E with respect to EdU incorporation as well as on a relationship between expression of cyclin A vs. p21(WAF1) and Ki-67 vs. Cdt1, are also reported. Of particular interest is the observation that this approach makes it possible to assess the temporal sequence of degradation of cyclin D1, p21(WAF1), Cdt1 and p12, each with respect to initiation of DNA replication and with respect to each other. Also the sequence or reappearance of these proteins in G2 after termination of DNA replication is assessed. The reviewed data provide a more comprehensive presentation of potential markers, whose presence or absence marks the DNA replicating cells. Discussed is also usefulness of these markers as indicators of proliferative activity in cancer tissues that may bear information on tumor progression and have a prognostic value.
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Affiliation(s)
- Zbigniew Darzynkiewicz
- Brander Cancer Research Institute, Department of Pathology, New York Medical College, Valhalla, NY
| | - Hong Zhao
- Brander Cancer Research Institute, Department of Pathology, New York Medical College, Valhalla, NY
| | - Sufang Zhang
- Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, NY
| | - Y.W.T. Lee Marietta
- Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, NY
| | - Y.C. Lee Ernest
- Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, NY
| | - Zhongtao Zhang
- Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, NY
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Weis MC, Avva J, Jacobberger JW, Sreenath SN. A data-driven, mathematical model of mammalian cell cycle regulation. PLoS One 2014; 9:e97130. [PMID: 24824602 PMCID: PMC4019653 DOI: 10.1371/journal.pone.0097130] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2013] [Accepted: 04/15/2014] [Indexed: 12/15/2022] Open
Abstract
Few of >150 published cell cycle modeling efforts use significant levels of data for tuning and validation. This reflects the difficultly to generate correlated quantitative data, and it points out a critical uncertainty in modeling efforts. To develop a data-driven model of cell cycle regulation, we used contiguous, dynamic measurements over two time scales (minutes and hours) calculated from static multiparametric cytometry data. The approach provided expression profiles of cyclin A2, cyclin B1, and phospho-S10-histone H3. The model was built by integrating and modifying two previously published models such that the model outputs for cyclins A and B fit cyclin expression measurements and the activation of B cyclin/Cdk1 coincided with phosphorylation of histone H3. The model depends on Cdh1-regulated cyclin degradation during G1, regulation of B cyclin/Cdk1 activity by cyclin A/Cdk via Wee1, and transcriptional control of the mitotic cyclins that reflects some of the current literature. We introduced autocatalytic transcription of E2F, E2F regulated transcription of cyclin B, Cdc20/Cdh1 mediated E2F degradation, enhanced transcription of mitotic cyclins during late S/early G2 phase, and the sustained synthesis of cyclin B during mitosis. These features produced a model with good correlation between state variable output and real measurements. Since the method of data generation is extensible, this model can be continually modified based on new correlated, quantitative data.
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Affiliation(s)
- Michael C. Weis
- Department of Electrical Engineering and Computer Science, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Jayant Avva
- Department of Electrical Engineering and Computer Science, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - James W. Jacobberger
- Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, Ohio, United States of America
- * E-mail:
| | - Sree N. Sreenath
- Department of Electrical Engineering and Computer Science, Case Western Reserve University, Cleveland, Ohio, United States of America
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14
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Darzynkiewicz Z, Zhao H, Halicka HD, Li J, Lee YS, Hsieh TC, Wu JM. In search of antiaging modalities: evaluation of mTOR- and ROS/DNA damage-signaling by cytometry. Cytometry A 2014; 85:386-99. [PMID: 24677687 DOI: 10.1002/cyto.a.22452] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2014] [Revised: 02/06/2014] [Accepted: 06/02/2014] [Indexed: 12/31/2022]
Abstract
This review presents the evidence in support of the IGF-1/mTOR/S6K1 signaling as the primary factor contributing to aging and cellular senescence. Reviewed are also specific interactions between mTOR/S6K1 and ROS-DNA damage signaling pathways. Outlined are critical sites along these pathways, including autophagy, as targets for potential antiaging (gero-suppressive) and/or chemopreventive agents. Presented are applications of flow- and laser scanning- cytometry utilizing phospho-specific Abs, to monitor activation along these pathways in response to the reported antiaging drugs rapamycin, metformin, berberine, resveratrol, vitamin D3, 2-deoxyglucose, and acetylsalicylic acid. Specifically, effectiveness of these agents to attenuate the level of constitutive mTOR signaling was tested by cytometry and confirmed by Western blotting through measuring phosphorylation of the mTOR-downstream targets including ribosomal protein S6. The ratiometric analysis of phosphorylated to total protein along the mTOR pathway offers a useful parameter reporting the effects of gero-suppressive agents. In parallel, their ability to suppress the level of constitutive DNA damage signaling induced by endogenous ROS was measured. While the primary target of each of these agents may be different the data obtained on several human cancer cell lines, WI-38 fibroblasts and normal lymphocytes suggest common downstream mechanism in which the decline in mTOR/S6K1 signaling and translation rate is coupled with a reduction of oxidative phosphorylation and ROS that leads to decreased oxidative DNA damage. The combined assessment of constitutive γH2AX expression, mitochondrial activity (ROS, ΔΨm), and mTOR signaling provides an adequate gamut of cell responses to test effectiveness of gero-suppressive agents. Described is also an in vitro model of induction of cellular senescence by persistent replication stress, its quantitative analysis by laser scanning cytometry, and application to detect the property of the studied agents to attenuate the induction of senescence. Discussed is cytometric analysis of cell size and heterogeneity of size as a potential biomarker used to asses gero-suppressive agents and longevity.
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Affiliation(s)
- Zbigniew Darzynkiewicz
- Brander Cancer Research Institute and Department of Pathology, New York Medical College, Valhalla, New York, 10595
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15
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Zhao H, Halicka HD, Li J, Darzynkiewicz Z. Berberine suppresses gero-conversion from cell cycle arrest to senescence. Aging (Albany NY) 2013; 5:623-36. [PMID: 23974852 PMCID: PMC3796215 DOI: 10.18632/aging.100593] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2013] [Accepted: 08/20/2013] [Indexed: 01/05/2023]
Abstract
Berberine (BRB), a natural alkaloid, has a long history of medicinal use in both Ayurvedic and old Chinese medicine. Recently, available as a dietary supplement, Berberine is reported to have application in treatment of variety diseases. Previously we observed that BRB inhibited mTOR/S6 signaling concurrently with reduction of the level of endogenous oxidants and constitutive DNA damage response. We currently tested whether Berberine can affect premature, stress-induced cellular senescence caused by mitoxantrone. The depth of senescence was quantitatively measured by morphometric parameters, senescence-associated β-galactosidase, induction of p21WAF1, replication stress (γH2AX expression), and mTOR signaling; the latter revealed by ribosomal S6 protein (rpS6) phosphorylation. All these markers of senescence were distinctly diminished, in a concentration-dependent manner, by Berberine. In view of the evidence that BRB localizes in mitochondria, inhibits respiratory electron chain and activates AMPK, the observed attenuation of the replication stress-induced cellular senescence most likely is mediated by AMPK that leads to inhibition of mTOR signaling. In support of this mechanism is the observation that rhodamine123, the cationic probe targeting mitochondrial electron chain, also suppressed rpS6 phosphorylation. The present findings reveal that: (a) in cells induced to senescence BRB exhibits gero-suppressive properties by means of mTOR/S6 inhibition; (b) in parallel, BRB reduces the level of constitutive DNA damage response, previously shown to report oxidative DNA damage by endogenous ROS; (c) there appears to a causal linkage between the (a) and (b) activities; (d) the in vitro model of premature stress-induced senescence can be used to assess effectiveness of potential gero-suppressive agents targeting mTOR/S6 and ROS signaling; (e) since most of the reported beneficial effects of BRB are in age-relate diseases, it is likely that gero-suppression is the primary activity of this traditional medicine.
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Affiliation(s)
- Hong Zhao
- Brander Cancer Research Institute and Department of Pathology, New York Medical College, Valhalla, NY 10595, USA
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16
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Affiliation(s)
- Zbigniew Darzynkiewicz
- Brander Cancer Research Institute and Department of Pathology, New York Medical College, Valhalla, NY, USA.
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17
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Wee LM, Flores-Jasso CF, Salomon WE, Zamore PD. Argonaute divides its RNA guide into domains with distinct functions and RNA-binding properties. Cell 2012; 151:1055-67. [PMID: 23178124 PMCID: PMC3595543 DOI: 10.1016/j.cell.2012.10.036] [Citation(s) in RCA: 272] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2012] [Revised: 09/11/2012] [Accepted: 10/08/2012] [Indexed: 12/13/2022]
Abstract
MicroRNAs (miRNAs) and small interfering RNAs (siRNAs) guide Argonaute proteins to silence mRNA expression. Argonaute binding alters the properties of an RNA guide, creating functional domains. We show that the domains established by Argonaute-the anchor, seed, central, 3' supplementary, and tail regions-have distinct biochemical properties that explain the differences between how animal miRNAs and siRNAs bind their targets. Extensive complementarity between an siRNA and its target slows the rate at which fly Argonaute2 (Ago2) binds to and dissociates from the target. Highlighting its role in antiviral defense, fly Ago2 dissociates so slowly from extensively complementary target RNAs that essentially every fully paired target is cleaved. Conversely, mouse AGO2, which mainly mediates miRNA-directed repression, dissociates rapidly and with similar rates for fully paired and seed-matched targets. Our data narrow the range of biochemically reasonable models for how Argonaute-bound siRNAs and miRNAs find, bind, and regulate their targets.
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Affiliation(s)
- Liang Meng Wee
- Department of Biochemistry and Molecular Pharmacology and Howard Hughes Medical Institute, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - C. Fabián Flores-Jasso
- Department of Biochemistry and Molecular Pharmacology and Howard Hughes Medical Institute, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - William E. Salomon
- Department of Biochemistry and Molecular Pharmacology and Howard Hughes Medical Institute, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Phillip D. Zamore
- Department of Biochemistry and Molecular Pharmacology and Howard Hughes Medical Institute, University of Massachusetts Medical School, Worcester, MA 01605, USA
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18
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Darzynkiewicz Z, Halicka HD, Zhao H, Podhorecka M. Cell synchronization by inhibitors of DNA replication induces replication stress and DNA damage response: analysis by flow cytometry. Methods Mol Biol 2011; 761:85-96. [PMID: 21755443 PMCID: PMC3137244 DOI: 10.1007/978-1-61779-182-6_6] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Abstract
Cell synchronization is often achieved by inhibition of DNA replication. The cells cultured in the presence of such inhibitors as hydroxyurea, aphidicolin, or thymidine become arrested at the entrance to S phase and upon release from the block they synchronously progress through S, G(2), and M. We recently reported that exposure of cells to these inhibitors at concentrations commonly used to synchronize cell populations led to phosphorylation of histone H2AX on Ser139 (induction of γH2AX) through activation of ataxia telangiectasia mutated and Rad3-related protein kinase (ATR). These findings imply that the induction of DNA replication stress by these inhibitors activates the DNA damage response signaling pathways and caution about interpreting data obtained with use of cells synchronized such way as representing unperturbed cells. The protocol presented in this chapter describes the methodology of assessment of phosphorylation of histone H2AX-Ser139, ATM/ATR substrate on Ser/Thr at SQ/TQ cluster domains as well as ataxia telangiectasia mutated (ATM) protein kinase in cells treated with inhibitors of DNA replication. Phosphorylation of these proteins is detected in individual cell immunocytochemically with phospho-specific antibody (Ab) and measured by flow cytometry. Concurrent measurement of cellular DNA content and phosphorylated proteins followed by multiparameter cytometric analysis allows one to correlate extent of their phosphorylation with cell cycle phase.
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Affiliation(s)
- Zbigniew Darzynkiewicz
- Department of Pathology, Brander Cancer Research Institute, New York Medical College, 10595, Valhalla, NY, USA.
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19
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Effects of hydroxyurea on monoclonal antibody production induced by anti-mIgG and LPS stimulation on murine B cell hybridomas. Cytotechnology 2010; 62:205-15. [PMID: 20490659 DOI: 10.1007/s10616-010-9278-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2009] [Accepted: 05/05/2010] [Indexed: 10/19/2022] Open
Abstract
Chemical treatment with hydroxyurea (HU) has been selected as a simple and low cost strategy to generate a cell population enriched for the G1 phase. After the chemical treatment with HU, cells were stimulated with anti-mIgG to test if the positive effects of anti-mIgG on CD40 expression and specific IgG2a production rate were improved upon a cell population with a higher percentage of cells in G1 phase at the beginning of the cell culture. In addition, other treatments assayed in this work were the cell stimulation with Lipopolysaccharide (LPS) both before and after the HU treatment. It has been observed that the use of HU under conditions able to maintain the cells in viable state (0.1 mM for 20 h), has a negative effect on CD40 expression and specific IgG2a production rate induced by anti-mIgG. The positive effect of LPS on cell stimulation induced by anti-mIgG is reduced on cells treated with HU.
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20
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Park K, Jang J, Irimia D, Sturgis J, Lee J, Robinson JP, Toner M, Bashir R. 'Living cantilever arrays' for characterization of mass of single live cells in fluids. LAB ON A CHIP 2008; 8:1034-41. [PMID: 18584076 PMCID: PMC3804646 DOI: 10.1039/b803601b] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
The size of a cell is a fundamental physiological property and is closely regulated by various environmental and genetic factors. Optical or confocal microscopy can be used to measure the dimensions of adherent cells, and Coulter counter or flow cytometry (forward scattering light intensity) can be used to estimate the volume of single cells in a flow. Although these methods could be used to obtain the mass of single live cells, no method suitable for directly measuring the mass of single adherent cells without detaching them from the surface is currently available. We report the design, fabrication, and testing of 'living cantilever arrays', an approach to measure the mass of single adherent live cells in fluid using silicon cantilever mass sensor. HeLa cells were injected into microfluidic channels with a linear array of functionalized silicon cantilevers and the cells were subsequently captured on the cantilevers with positive dielectrophoresis. The captured cells were then cultured on the cantilevers in a microfluidic environment and the resonant frequencies of the cantilevers were measured. The mass of a single HeLa cell was extracted from the resonance frequency shift of the cantilever and was found to be close to the mass value calculated from the cell density from the literature and the cell volume obtained from confocal microscopy. This approach can provide a new method for mass measurement of a single adherent cell in its physiological condition in a non-invasive manner, as well as optical observations of the same cell. We believe this technology would be very valuable for single cell time-course studies of adherent live cells.
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Affiliation(s)
- Kidong Park
- Birck Nanotechnology Center, Purdue University, West Lafayette, IN, 47907, USA
- School of Electrical and Computer Engineering, Purdue University, West Lafayette, IN, 47907, USA
| | - Jaesung Jang
- Now at Department of Mechanical Engineering, Chung-Ang University, Seoul, 156-756, S. Korea
| | - Daniel Irimia
- BioMEMS Resource Center, Center for Engineering in Medicine and Surgical Services, Massachusetts General Hospital, Shriners Hospital for Children, and Harvard Medical School, Boston, MA, 02129, USA
| | - Jennifer Sturgis
- Bindley Biosciences Center, Purdue University, West Lafayette, IN, 47907, USA
- Department of Basic Medical Sciences, Purdue University, West Lafayette, IN, 47907, USA
| | - James Lee
- Department of Chemical Engineering, The Ohio State University, Columbus, OH, 43210, USA
| | - J. Paul Robinson
- Bindley Biosciences Center, Purdue University, West Lafayette, IN, 47907, USA
- Department of Basic Medical Sciences, Purdue University, West Lafayette, IN, 47907, USA
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, 47907, USA
| | - Mehmet Toner
- BioMEMS Resource Center, Center for Engineering in Medicine and Surgical Services, Massachusetts General Hospital, Shriners Hospital for Children, and Harvard Medical School, Boston, MA, 02129, USA
| | - Rashid Bashir
- Micro and Nanotechnology Laboratory, Department of Electrical and Computer Engineering & Bioengineering, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
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Snapka RM, Ge S, Trask J, Robertson F. Unbalanced growth in mouse cells with amplified
dhfr
genes. Cell Prolif 2008. [DOI: 10.1111/j.1365-2184.1997.tb00918.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Affiliation(s)
- R. M. Snapka
- Department of Radiology, The Ohio State University College of Medicine, Columbus, Ohio, USA
- Department of Medical Microbiology and Immunology, The Ohio State University College of Medicine, Columbus, Ohio, USA
| | - S. Ge
- Department of Radiology, The Ohio State University College of Medicine, Columbus, Ohio, USA
| | - J. Trask
- Department of Medical Microbiology and Immunology, The Ohio State University College of Medicine, Columbus, Ohio, USA
| | - F. Robertson
- Department of Medical Microbiology and Immunology, The Ohio State University College of Medicine, Columbus, Ohio, USA
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22
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Banfalvi G. Cell cycle synchronization of animal cells and nuclei by centrifugal elutriation. Nat Protoc 2008; 3:663-73. [DOI: 10.1038/nprot.2008.34] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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23
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Mandecki W, Ardelt B, Coradetti T, Davidowitz H, AFlint JA, Huang Z, MKopacka WM, Lin X, Wang Z, Darzynkiewicz Z. Microtransponders, the miniature RFID electronic chips, as platforms for cell growth in cytotoxicity assays. Cytometry A 2006; 69:1097-105. [PMID: 17051582 DOI: 10.1002/cyto.a.20344] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
BACKGROUND An electronic radio frequency (RF) microchip, the microtransponder (MTP), has been developed as a platform for assays in the fields of genomics and proteomics. Upon activation by light, each MTP provides a unique RF identification (ID) signal that matches a chip to the specific biological material attached to it. The MTP is powered by a photocell and has an antenna that transmits the signal. The aim of the present study was to explore utility of MTPs as a platform for cell growth in cytotoxicity assays. METHODS The MCF-7, MCF-116, A549, or T-24 cells growing on MTPs placed in petri dishes or slide chambers were cultured untreated or exposed to antitumor drugs topotecan, mitoxantrone, or onconase for up to 4 days. Their attachment to- and growth on- MTPs was assessed by fluorescence microscopy and laser scanning cytometry (LSC) and compared with growth on the dish surface in the MTP neighborhood. The MTPs were fixed in ethanol, stained with propidium iodide (PI), and interrogated in flow in the instrument capable to rapidly (up to 103 MTPs/s) identify their ID signal and measure fluorescence. RESULTS The cells plated on MTPs exhibited similar attachment properties to those plated in culture dishes. When measured by LSC, they had similar mitotic activity, growth rate, and cell cycle distributions as the cells adhering to the culture dish in the neighborhood of MTPs. The fluorescence intensity of MTPs provided information about the cell number per MTP, which made it possible to assess cell growth rate and monitor the cytostatic/cytotoxic effects of the tested drugs. CONCLUSIONS The MTP-based system holds promise for the multiplexed cell assays in which numerous different cell lines can be screened for their growth rate or sensitivity while exposed to particular agents in the same vessel. Other advantages of the system are the rapidity of the screening and a very large number of ID codes. Because many cell lines/types can be assayed in a single dish, the system also offers cost savings on tissue culture reagents.
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24
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Kurose A, Tanaka T, Huang X, Traganos F, Darzynkiewicz Z. Synchronization in the cell cycle by inhibitors of DNA replication induces histone H2AX phosphorylation: an indication of DNA damage. Cell Prolif 2006; 39:231-40. [PMID: 16672000 PMCID: PMC6496703 DOI: 10.1111/j.1365-2184.2006.00380.x] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Several methods to synchronize cultured cells in the cell cycle are based on temporary inhibition of DNA replication. Previously it has been reported that cells synchronized this way exhibited significant growth imbalance and unscheduled expression of cyclins A and B1. We have now observed that HL-60 cells exposed to inhibitors of DNA replication (thymidine, aphidicolin and hydroxyurea), at concentrations commonly used to synchronize cell populations, had histone H2AX phosphorylated on Ser-139. This modification of H2AX, a marker of DNA damage (induction of DNA double-strand breaks; DSBs), was most pronounced in S-phase cells, and led to their apoptosis. Thus, to a large extent, synchronization was caused by selective kill of DNA replicating cells through induction of replication stress. In fact, similar synchronization has been achieved by exposure of cells to the DNA topoisomerase I inhibitor camptothecin, a cytotoxic drug known to target S-phase cells. A large proportion of the surviving cells 'synchronized' by DNA replication inhibitors at the G1/S boundary had phosphorylated histone H2AX. Inhibitors of DNA replication, thus, not only selectively kill DNA replicating cells, induce growth imbalance and alter the machinery regulating progression through the cycle, but they also cause DNA damage involving formation of DSBs in the surviving ('synchronized') cells. The above effects should be taken into account when interpreting data obtained with the use of cells synchronized by inhibitors of DNA replication.
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Affiliation(s)
- A. Kurose
- Brander Cancer Research Institute and
- Department of Pathology, New York Medical College, Valhalla, NY 10595, USA
- Department of Pathology, Iwate Medical University, 19‐1 Uchimaru, Morioka, Iwate 020‐8505, Japan, and
| | - T. Tanaka
- Brander Cancer Research Institute and
- First Department of Surgery, Yamaguchi University School of Medicine 1‐1‐1 Minami‐kogushi, Ube, Yamaguchi 755‐8505, Japan
| | - X. Huang
- Brander Cancer Research Institute and
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25
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Affiliation(s)
- Frank Traganos
- Brander Cancer Research Institute, New York Medical College, Hawthorne, New York 10532, USA
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26
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Sun H, Tu X, Prisco M, Wu A, Casiburi I, Baserga R. Insulin-like growth factor I receptor signaling and nuclear translocation of insulin receptor substrates 1 and 2. Mol Endocrinol 2003; 17:472-86. [PMID: 12554758 DOI: 10.1210/me.2002-0276] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The insulin receptor substrate 1 (IRS-1) can translocate to the nuclei and nucleoli of several types of cells. Nuclear translocation can be induced by an activated insulin-like growth factor 1 receptor (IGF-IR), and by certain oncogenes, such as the Simian virus 40 T antigen and v-src. We have asked whether IRS-2 could also translocate to the nuclei. In addition, we have studied the effects of functional mutations in the IGF-IR on nuclear translocation of IRS proteins. IRS-2 translocates to the nuclei of mouse embryo fibroblasts expressing the IGF-IR, but, at variance with IRS-1, does not translocate in cells expressing the Simian virus 40 T antigen. Mutations in the tyrosine kinase domain of the IGF-IR abrogate translocation of the IRS proteins. Other mutations in the IGF-IR, which do not interfere with its mitogenicity but inhibit its transforming capacity, result in a decrease in translocation, especially to the nucleoli. Nuclear IRS-1 and IRS-2 interact with the upstream binding factor, which is a key regulator of RNA polymerase I activity and, therefore, rRNA synthesis. In 32D cells, wild-type, but not mutant, IRS-1 causes a significant activation of the ribosomal DNA promoter. The interaction of nuclear IRS proteins with upstream binding factor 1 constitutes the first direct link of these proteins with the ribosomal DNA transcription machinery.
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Affiliation(s)
- HongZhi Sun
- Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, USA
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27
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Tu X, Batta P, Innocent N, Prisco M, Casaburi I, Belletti B, Baserga R. Nuclear translocation of insulin receptor substrate-1 by oncogenes and Igf-I. Effect on ribosomal RNA synthesis. J Biol Chem 2002; 277:44357-65. [PMID: 12202493 DOI: 10.1074/jbc.m208001200] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The insulin receptor substrate-1 (IRS-1) is one of the major substrates of both the insulin and IGF-I receptors and is generally localized in the cytosol/membrane fraction of the cell. We show here that a substantial fraction of IRS-1 is translocated to the nucleus in mouse embryo fibroblasts (MEF) expressing the simian virus 40 T antigen. Nuclear translocation of IRS-1 occurs also in MEF stimulated with IGF-I or in MEF expressing the oncogene v-src. Nuclear translocation of IRS-1 can be demonstrated by confocal microscopy, immunohistochemistry, or subcellular fractionation. An antibody to IRS-1 immunoprecipitates from nuclear fractions (but not from cytosolic fractions) the upstream binding factor, which is a key regulator of RNA polymerase I activity and ribosomal RNA (rRNA) synthesis. In agreement with this finding, in 32D murine hemopoietic cells, nuclear translocation of IRS-1 correlates with a markedly increased rRNA synthesis. Our experiments suggest that nuclear IRS-1 may play a specialized role in rRNA synthesis and/or processing.
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Affiliation(s)
- Xiao Tu
- Kimmel Cancer Center, Thomas Jefferson University, 233 South 10th Street, 624 BLSB, Philadelphia, Pennsylvania 19107, USA
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28
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Prisco M, Santini F, Baffa R, Liu M, Drakas R, Wu A, Baserga R. Nuclear translocation of insulin receptor substrate-1 by the simian virus 40 T antigen and the activated type 1 insulin-like growth factor receptor. J Biol Chem 2002; 277:32078-85. [PMID: 12063262 DOI: 10.1074/jbc.m204658200] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
32D cells are a murine hemopoietic cell line that undergoes apoptosis upon withdrawal of interleukin-3 (IL-3) from the medium. 32D cells have low levels of the type 1 insulin-like growth factor (IGF-I) receptor and do not express insulin receptor substrate-1 (IRS-1) or IRS-2. Ectopic expression of IRS-1 delays apoptosis but cannot rescue 32D cells from IL-3 dependence. In 32D/IRS-1 cells, IRS-1 is detectable, as expected, in the cytosol/membrane compartment. The SV40 large T antigen is a nuclear protein that, by itself, also fails to protect 32D cells from apoptosis. Co-expression of IRS-1 with the SV40 T antigen in 32D cells results in nuclear translocation of IRS-1 and survival after IL-3 withdrawal. Expression of a human IGF-I receptor in 32D/IRS-1 cells also results in nuclear translocation of IRS-1 and IL-3 independence. The phosphotyrosine-binding domain, but not the pleckstrin domain, is necessary for IRS-1 nuclear translocation. Nuclear translocation of IRS-1 was confirmed in mouse embryo fibroblasts. These results suggest possible new roles for nuclear IRS-1 in IGF-I-mediated growth and anti-apoptotic signaling.
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Affiliation(s)
- Marco Prisco
- Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, USA
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Jackman AL, Boyle FT, Harrap KR. Tomudex (ZD1694): from concept to care, a programme in rational drug discovery. Invest New Drugs 1996; 14:305-16. [PMID: 8958186 DOI: 10.1007/bf00194534] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Folate-based anticancer drugs with specificity for thymidylate synthase (TS) have come of age. Ideas nurtured in the early 1970s led to the first-generation of antifolates with TS and dihydrofolate reductase (DHFR) inhibitory activities. Compounds with increased selectivity for TS followed with the highly specific inhibitor, CB3717 being synthesised in 1979 at the Institute of Cancer Research (ICR). CB3717 had significant clinical activity but its development had to be abandoned because its low aqueous solubility led to occasional nephrotoxicity. Collaborative laboratory studies between the ICR and ICI Pharmaceuticals (later to become Zeneca Pharmaceuticals) led to the discovery of ZD1694 (Tomudex), the first antifolate to be licensed for the treatment of cancer (UK 1995) in nearly 40 years and the first new drug for colorectal cancer in about 35 years. Tomudex belongs to a class of compounds that use the reduced-folate carrier (RFC) for uptake into cells and which are excellent substrates for folylpolyglutamate synthetase (FPGS). This paper reviews the underlying philosophies, and the milestones reached during the development of Tomudex.
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Affiliation(s)
- A L Jackman
- CRC Centre for Cancer Therapeutics, Institute of Cancer Research, Sutton, Surrey, UK
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30
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Seither RL, Rape TJ, Goldman ID. Interconversion of tetrahydrofolate cofactors to dihydrofolate induced by trimetrexate after suppression of thymidylate synthase by fluorodeoxyuridine in L1210 leukemia cells. Biochem Pharmacol 1992; 43:2647-54. [PMID: 1385949 DOI: 10.1016/0006-2952(92)90154-b] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Previous studies from this laboratory demonstrated that marked suppression of thymidylate synthase activity is required to slow the rate of interconversion of tetrahydrofolate cofactors to dihydrofolate when dihydrofolate reductase is blocked by an antifolate. This finding is due to the high catalytic activity of thymidylate synthase within cells in comparison to the tetrahydrofolate cofactor pool size. In the present study, we assessed the rate of resumption of thymidylate synthase catalytic activity in terms of [3H]deoxyuridine incorporation into DNA and dihydrofolate generation from tetrahydrofolate cofactors following exposure of cells to fluorodeoxyuridine. Log phase L1210 leukemia cells, incubated with fluorodeoxyuridine to abolish thymidylate synthase catalytic activity, were suspended into drug-free medium. Resumption of [3H]deoxyuridine incorporation into DNA was negligible; by 4 hr enzyme activity was still inhibited by approximately 98%. However, this was sufficient to interconvert all available tetrahydrofolate cofactors to dihydrofolate (T1/2 approximately 2 hr) when dihydrofolate reductase was inhibited by the lipophilic antifolate trimetrexate. Interconversion of tetrahydrofolate cofactors to dihydrofolate correlated with a decline, then cessation, of purine synthesis as measured by the incorporation of [14C]formate into purine bases. These data suggest that an earlier than previously expected depletion of tetrahydrofolate cofactors with consequent inhibition of purine and other folate-dependent synthetic processes is likely to occur when antifolates are administered after a fluoropyrimidine.
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Affiliation(s)
- R L Seither
- Department of Medicine, Virginia Commonwealth University, Medical College of Virginia, Richmond 23298
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31
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Goswami PC, Higashikubo R, Tolmach LJ, Roti Roti JL. G1 shortening following unbalanced growth: a specific v. nonspecific effect. Cell Prolif 1992; 25:251-60. [PMID: 1596538 DOI: 10.1111/j.1365-2184.1992.tb01400.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The synthesis and abundance of proteins were examined in synchronous populations of HeLa cells under conditions in which the lengthening of S phase, by inhibiting DNA synthesis, resulted in shortening of G1 in the subsequent generation. Mitotically collected cells were resynchronized by incubation with 3 microM aphidicolin from 3 to 12 h after mitotic selection; they were blocked again at various times thereafter to induce unbalanced growth. Cells were labelled with [35S]-methionine before and after release from the block to study the changes in protein synthesis. Triton X-100 soluble and insoluble proteins were analysed by 7-15% gradient SDS-PAGE, and radioactivity incorporation was quantified by liquid-scintillation counting. The degree of G1 shortening correlated with S phase position, increasing gradually from early S and reaching maximum when cells were blocked half-way through S phase. Synthesis of proteins of 120, 66, and 51 kDa was stimulated, and synthesis of a new protein of 57kDa was observed, in cells in which DNA synthesis had been blocked in mid-S. These proteins also showed increased accumulation. These results suggest that the shortening of G1, induced by the prior arrest of cell-cycle progression, is associated with synthesis of specific proteins rather than the non-specific accumulation of cellular proteins through unbalanced growth.
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Affiliation(s)
- P C Goswami
- Section of Cancer Biology, Washington University Medical Center, St. Louis, MO 63108
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32
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Supino R, Mariani M, Colombo A, Prosperi E, Croce AC, Bottiroli G. Comparative studies on the effects of doxorubicin and differentiation inducing agents on B16 melanoma cells. Eur J Cancer 1992; 28A:778-83. [PMID: 1326307 DOI: 10.1016/0959-8049(92)90114-h] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The differentiation-inducing activity of doxorubicin on B16 melanoma cells grown in vitro was compared with that of other known differentiation inducers, such as theophylline, retinoic acid, and melanocyte-stimulating hormone (MSH). At drug concentrations resulting in cytostatic effects, doxorubicin and theophylline induced morphological changes (dendritic-like structures with a terminal melanin granule) with an enhancement of total melanin content and tyrosinase activity. Retinoic acid did not alter melanin content and cell morphology, although it affected cell growth. MSH enhanced total melanin content and tyrosinase activity, with no significant morphological changes. Flow cytometric analysis showed that MSH led to an accumulation of cells in G1 phase whereas doxorubicin induced an accumulation of cells in G2 + M. Studies on DNA content in doxorubicin-treated cells, selected on the basis of a morphologically differentiated pattern, showed a clustering of these cells in G2 + M, probably due to a cytokinesis block. Thus doxorubicin can induce cell differentiation comparable with other differentiation inducers.
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Affiliation(s)
- R Supino
- Istituto Nazionale Tumori, Milan, Italy
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33
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Sennerstam R, Stromberg JO. Dissociation of Cell Growth and DNA Synthesis and Alteration of the Nucleo-Cytoplasmic Ratio in Growing Embryonal Carcinoma Cells. (nucleo-cytoplasmic ratio/cell cycle/differentiation). Dev Growth Differ 1991. [DOI: 10.1111/j.1440-169x.1991.00353.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Engelhard HH, Krupka JL, Bauer KD. Simultaneous quantification of c-myc oncoprotein, total cellular protein, and DNA content using multiparameter flow cytometry. CYTOMETRY 1991; 12:68-76. [PMID: 1900228 DOI: 10.1002/cyto.990120110] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Variations in total cellular protein content can confound interpretation of the significance of modulations of specific cellular proteins. In an effort to overcome this problem, a technique is described for the simultaneous measurement of a specific cellular protein, total cellular protein, and DNA content. The method utilizes dual-laser (uv and 488 nm) excitation and three fluorescent dyes: FITC, SR101, and DAPI. FITC-labelled antibody coupled with indirect immunofluorescence was used to quantify the c-myc oncoprotein, whereas SR101 and DAPI were used to measure total cellular protein and cellular DNA, respectively. Flow cytometric measurements of c-myc oncoprotein were compared to densitometric readings of p64c-myc. SR101 protein determinations were compared to those obtained by the Lowry technique. Results indicated that flow cytometric measurements correlated well with those obtained by the biochemical methods. The usefulness of the technique was further examined following treatment of exponentially growing HL-60 cells with 2.5 micrograms/ml cycloheximide for 0 to 12 h. Cycloheximide treatment was found to cause a significant decrease in c-myc oncoprotein content within 2 h (P less than 0.05), a relative increase in the proportion of G0/G1 cells and a modest decrease in total cellular protein. This technique appears to provide a rapid, quantitative approach, useful for investigating alterations in cellular growth balance occurring with cell differentiation, neoplastic transformation, or cell treatment with radiation or cytostatic drugs.
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Affiliation(s)
- H H Engelhard
- Department of Pathology, Northwestern University Medical School, Chicago, Illinois 60611
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35
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Shrivastava R, Ratinaud MH, Julien R. Comparative flow cytometric analysis of bleomycin toxicity on normal and tumour sheep cell kinetics in vitro. J Appl Toxicol 1990; 10:99-103. [PMID: 1694537 DOI: 10.1002/jat.2550100207] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The cytotoxic effects of bleomycin on cell proliferation, morphology and cycle progression were compared in a sheep tumour cell line and in normal sheep sinus cells. They were concentration and time dependent, irreversible, and were accompanied by increased cell diameter and cytosolic synthetic activity. Cell accumulation in the G2M phase, without much change in the cell cycle progression through the S phase, was observed using flow cytometry. Although the tumour cells showed a greater sensitivity to low bleomycin concentrations compared to the normal cells, both cell types exhibited equal sensitivity to higher drug concentrations. Provided that tumour cells are also preferentially affected by bleomycin in vivo, these findings raise the possibility that bleomycin cytotoxicity can be reduced or avoided in normal tissue.
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36
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Differential toxicity of cytosine arabinoside to cell kinetics in normal sheep sinus cells and sheep tumour cell line in vitro. Toxicol In Vitro 1990; 4:143-7. [DOI: 10.1016/0887-2333(90)90036-s] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/1988] [Revised: 06/16/1989] [Indexed: 11/20/2022]
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37
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Chan TC, Howell SB. Unexpected synergy between N-phosphonacetyl-L-aspartate and cytidine against human tumor cells. EUROPEAN JOURNAL OF CANCER & CLINICAL ONCOLOGY 1989; 25:721-7. [PMID: 2714348 DOI: 10.1016/0277-5379(89)90209-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Cytidine, a non-toxic endogenous nucleoside, was found unexpectedly to augment the cytotoxicity of a pyrimidine antimetabolite N-phosphonacetyl-L-aspartate (PALA) in human ovarian carcinoma cells. The PALA/cytidine synergy is confirmed here in other human tumor cells (T242 melanoma, HL60 promyelocytic leukemia and SKOV3 ovarian carcinoma) in the cytidine concentration range of 1-10 micromolar. The synergy was not observed in Chinese hamster ovary (CHO) cells. Exogenous uridine (5-50 microM) completely reversed the PALA/cytidine cytotoxicity in a concentration-dependent manner. Measurements of cellular ribonucleotide levels revealed that the PALA treated cells had reduced UTP and CTP pools (10% and 40% of control respectively); and the PALA/cytidine treated cells had elevated CTP and GTP levels while their UTP levels remained at 10% of control. Deoxyribonucleotide levels were unremarkable except for a slight elevation of dCTP in the PALA/cytidine treated cells. Uridine competitively inhibited radioactive cytidine transport into 2008 cells, which may explain its ability to antagonize the PALA/cytidine synergy. These results suggest that the ribonucleotide biosynthetic mechanism is the primary cellular target for PALA/cytidine activity, and that the ratio of ribonucleotides to each other is an important determinant of tumor cell viability. The use of non-cytotoxic nucleosides to augment the activity of antimetabolites may have clinical relevance in cancer therapy.
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Affiliation(s)
- T C Chan
- Department of Physiology and Pharmacology, School of Veterinary Medicine, Purdue University, West Lafayette, Indiana 47907
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38
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Keyomarsi K, Moran RG. Mechanism of the cytotoxic synergism of fluoropyrimidines and folinic acid in mouse leukemic cells. J Biol Chem 1988. [DOI: 10.1016/s0021-9258(18)68234-1] [Citation(s) in RCA: 70] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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39
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Moran RG, Keyomarsi K, Patel R. Tumor cell responses to inhibition of thymidylate synthase. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1988; 244:71-83. [PMID: 2977717 DOI: 10.1007/978-1-4684-5607-3_7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Whether inhibition of thymidylate synthase is lethal to a population of tumor cells depends upon three factors: 1) the dependence of the cells upon de novo synthesis of thymidine nucleotides; 2) the length of time enzyme is inhibited and the requirement for thymidine nucleotides during this period; and 3) the biochemical responses of the cells to the initial inhibition of enzyme, many of which interfere with maintenance of thymidylate synthase in an inhibited state. Following inhibition of thymidylate synthase, deoxyuridylate accumulates, as does the cellular content of thymidylate synthase. In addition, the initially formed enzyme-inhibitor complexes dissociate. These biochemical sequelae alter the effectiveness of the blockade of thymidylate synthase in a time-dependent, continuously-changing manner. Whether cell kill occurs depends on whether the dynamic balance of these factors allows a sufficiently low enzymatic activity to be maintained for a long enough period of time. An analysis of this interaction of factors leads us to the conclusions that efficient tumor cell kill with fluoropyrimidines is best attained by combination with reduced folate cofactors and inhibitors of deoxypyrimidine biosynthesis. Each of these agents modifies the response of tumor cells with the result that the fluorodeoxyuridylate-induced inhibition of thymidylate synthase is maintained. This analysis also suggests that folate analogs inhibitory to thymidylate synthase are more compatible than pyrimidine analogs with inhibition of thymidylate synthase as an approach to cancer chemotherapy.
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Affiliation(s)
- R G Moran
- Department of Pediatrics, University of Southern California, Los Angeles
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40
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Malorni W, Formisano G, Molinari A. In vitro effects of 2,5 hexanedione on a melanoma cell line: a morphological study. Toxicology 1987; 43:269-82. [PMID: 3029899 DOI: 10.1016/0300-483x(87)90086-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The effect of 2,5 hexanedione (2,5 HD) on a cultured human melanoma cell line (JR8) was explored. The addition of the toxicant at noncytolitic concentrations (0.08-0.16%) to the monolayers for 24 and 48 h, resulted in an irreversible inhibition of cell proliferation. Cessation of melanoma cell proliferation was accompanied by wide changes in morphological features of cells still adhering to the substrate. Incubation with the toxicant seemed to induce a differentiative process characterized mainly by a significant increase in cell protrusions. Melanoma cells, losing their bipolar appearance, often increased cell size and developed long dendritic and axon-like processes sometimes ramified in distal portions. Electron microscopic observations established that a change in the polarized appearance of control cells often occurred with 2,5 HD treatment and that a regular arrangement of organelles and cytoskeletal elements was detectable within these dendritic and axon-like protrusions. Furthermore, immunocytochemical studies confirmed an involvement of microtubules and actin network within cell prolongations. After the differentiative process a necrotizing effect occurred, inducing a progressive loss of viable, dendritic cells after 4 or 5 days. Incubation with cyclic AMP was ineffective in control cells while after 2,5 HD treatment seemed to increase the survival rate of neuronal-like cells. Possible mechanisms for the growth inhibitory and differentiative effects of 2,5 HD were discussed.
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41
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42
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Pallavicini MG. Cytosine arabinoside: molecular, pharmacokinetic and cytokinetic considerations. Pharmacol Ther 1984; 25:207-38. [PMID: 6390467 DOI: 10.1016/0163-7258(84)90044-5] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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43
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Vogel W, Trautmann T, Hörler H, Pentz S. Cytogenetic and biochemical investigations on fibroblast cultures and clones with one and two active X chromosomes of a 69,XXY triploidy. Hum Genet 1983; 64:246-8. [PMID: 6309648 DOI: 10.1007/bf00279402] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Bromodeoxyuridine replication patterns showed that fibroblasts from a 69,XXY triploidy carried either one or two early replicating X chromosomes. The activity of alpha-galactosidase A measured in single cells fell into two classes with a ratio of 1:2. Dilute plating produced clones of both types with the activity of alpha-galactosidase A corresponding to the number of active X chromosomes. To our knowledge, this is the first report on clones of a triploidy with different numbers of active X chromosomes, and on a gene-dosage effect of an X-linked gene using triploid cells with one active X as control.
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44
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Rønning OW, Lindmo T. Progress through G1 and S in relation to net protein accumulation in human NHIK 3025 cells. Exp Cell Res 1983; 144:171-9. [PMID: 6840202 DOI: 10.1016/0014-4827(83)90451-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
We have investigated whether human NHIK 3025 cells are dependent upon a net increase in cellular protein content in order to traverse G1 and S. The increase in DNA and protein content was studied by means of two-parameter flow cytometry using populations of cells synchronized by mitotic selection. By adding 1 microM cycloheximide to the medium protein synthesis was partially inhibited, resulting in negligible net accumulation of protein. The cells were able to enter S and progress through S under such conditions. The latter was the case whether the cells had been accumulating protein during G1 or not. The results further indicate that the larger cells enter S earlier and traverse S at a higher rate than the smaller cells. Our conclusion is that net accumulation of protein does not seem to be a prerequisite for traverse through G1 and S, i.e. DNA replication may be dissociated from the general growth of cell mass.
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45
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Abstract
Over the last four years, investigations into the mechanism of interaction between bleomycin and DNA have been pursued at a rapid pace. This is, no doubt, because of the potential of bleomycin as a tool for molecular biology. It seems likely that the precise nature of the interaction between Fe(II), oxygen and bleomycin will be elucidated in the near future together with the nature of the binding between the complex and DNA. More information on the mechanism of strand scission including the involvement of free radical mechanisms and sequence specificity may also be expected. In contrast to this picture of rapid progress at the molecular level, interest in studies of bleomycin action at the cellular level appears to have waned. This is despite the fact that most of the important questions which have been raised regarding effects of the drug on cell cycle progression, the possibility of a selective action on on-cycling cells and the nature of 'recovery from potentially-lethal damage' remain unresolved. There is no doubt that, for most cell types, bleomycin produces a block at the early G2 stage of the cell cycle. There is considerable doubt, however, as to how many of the cells blocked for a significant period remain clonogenically viable. This question is amenable to being answered using a vital DNA stain, such as Hoechst 33342, and cell sorting but this does not appear to have been done. The relationship between G2 blockage and repair of DNA damage has also not been resolved. Neither has the question of whether or not DNA breaks which remain unrepaired are different in nature from the majority of repairable lesions. The data on the relative sensitivity of exponential and plateau phase cells are conflicting and their in vivo significance unclear. Well designed experiments to examine the bleomycin sensitivity of those cells in solid tumors which survive radiation treatment could help to answer this question. Evidence that the phenomenon of 'recovery from potentially lethal damage' is therapeutically-exploitable is mainly lacking. It would be of great relevance to known whether or not the effect can be observed in normal tissues. However, the evidence that the effect is not simply an artefact of clonogenic assay procedures is scanty and this possibility must be borne in mind.(ABSTRACT TRUNCATED AT 400 WORDS)
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46
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Okabe T, Ishizawa S, Ishii T, Kataoka K, Matsuki S. Erythrocyte aging changes evaluated by the deoxyuridine suppression test. J Am Geriatr Soc 1982; 30:626-31. [PMID: 7119328 DOI: 10.1111/j.1532-5415.1982.tb05058.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Many hematologic studies have shown that the erythrocyte count decreases while the size of the individual cell increases in the aged. This study was performed in order to (1) evaluate changes in the blood erythrocyte level and mean erythrocyte size in the elderly and (2) evaluate use of the deoxyuridine (dU) supression test to determine whether deficiency of vitamin B12 or folate plays any role in age-related changes of hematopoiesis. Selected for study were 102 healthy men whose ages ranged from 20 to 79 years. The erythrocyte count and hemoglobin level decreased significantly, whereas the mean corpuscular volume and mean corpuscular hemoglobin increased after 70 years of age. Fresh bone-marrow cells were obtained from 10 young (20-38 yr) and 10 aged (70-82 yr) men. Wickramasinghe's dU suppression test was modified by application of an automatic cell harvester. The results were normal in both groups. Thus, the route of dU to dTMP in a DNA synthetic pathway appeared intact, and there was no evidence of B12 or folate deficiency in the aged to explain the observed macrocytosis. However, 3H-thymidine uptake by nucleated bone-marrow cells was significantly decreased, and the ratio of 3H-uridine to 3H-thymidine uptake was greater in the old group than in the young group. These results could be explained by altered nucleic acid metabolism (unbalanced cell growth) or by a change in the proportion of the different fractions of nucleated cells.
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47
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Rønning OW, Seglen PO. The relation between protein accumulation and cell cycle traverse of human NHIK 3025 cells in unbalanced growth. J Cell Physiol 1982; 112:19-26. [PMID: 7107714 DOI: 10.1002/jcp.1041120105] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Human NHIK 3025 cells, synchronized by mitotic selection, were given 2 mM thymidine, which inhibited DNA synthesis without reducing the rate of protein accumulation. After removal of the thymidine the cells proceeded towards mitosis and cell division, with an S duration 2 hours shorter than, but a G2 and M duration nearly identical to that of the control cells. If cycloheximide (1.25 muM) was present together with thymidine, no net protein accumulation took place during the treatment, and the subsequent duration of S, G2, and M was similar to that of untreated cells. The shortening of S seen after treatment with thymidine alone would therefore indicate that the rate of DNA synthesis depended on the amount of some preaccumulated protein. The postreplicative period in thymidine-treated cells was lengthened by cycloheximide treatment although the protein content had already been doubled. This suggests that proteins required for the traverse of this part of the cell cycle might have to be synthesized after completion of DNA replication. Shortly after removal of thymidine, the rate of protein accumulation declined markedly, indicating the existence of some mechanism for negative control of cell mass. In addition, the daughters of thymidine-treated cells had their cell cycle shortened by 2 hours. As a result, the cells had returned to balanced growth already in the first cell cycle following the induction of unbalanced growth. In conclusion, our experiments suggest that NHIK 3025 cells might require a minimum time in order to traverse the cell cycle, which is independent of cell mass.
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48
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Valeriote F. Cellular aspects of the action of cytosine arabinoside. MEDICAL AND PEDIATRIC ONCOLOGY 1982; 10 Suppl 1:5-26. [PMID: 7162467 DOI: 10.1002/mpo.2950100704] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
The cellular effects of Ara-C are reviewed including its S-phase sensitivity, its proliferative-dependent cytotoxicity and progression delay effects which result in unbalance growth. Both direct and indirect cytotoxic mechanisms are discussed. The impact of such cellular information on the scheduling of Ara-C is presented with regard to normal and tumor cell population cytotoxicity. Based on these data a therapeutic rationale is presented.
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49
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Ross DW. The nature of unbalanced cell growth caused by cytotoxic agents. VIRCHOWS ARCHIV. B, CELL PATHOLOGY INCLUDING MOLECULAR PATHOLOGY 1981; 37:225-35. [PMID: 6115510 DOI: 10.1007/bf02892571] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The volume of cells grown in tissue culture following exposure to a wide variety of cytotoxic drugs or x-rays increases at a rate of 1 to 10% of cell mass per hour. The same phenomenon is seen in animal neoplasias and human leukemias. This increase in cell volume is the result of unbalanced cell growth with a resulting disproportionate synthesis of proteins and possibly other macromolecules in the cytoplasm and nucleus. The dose response curve for a decrease in cell survival as measured by cloning efficiency in tissue culture is quantitatively correlated with the dose response curve for inducing an increase in cell volume. This quantitative relationship makes feasible the use of the phenomenon of unbalanced cell growth as a measure of cell death in screening for cytotoxic drugs or in monitoring response to therapy. An hypothesis to explain this increase in cell volume following chemotherapy is that cells are by the action of these drugs induced into an abortive or unbalanced pseudo-cycle which is characterized by synthesis of substantial amounts of protein without other preparative steps for cell division.
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50
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Abstract
The shape of the initial part of the dose-dependent response curve of LoVo cells, an established human colon carcinoma cell line, exposed for 1 hr to graded concentrations of 5-FU depended on the medium supplement, i.e., fetal calf serum (FCS), in which the cells were treated and subsequently incubated for colony-formation. At concentrations of 50--100 micrograms/ml (equivalent to peak plasma levels following an in vivo bolus dose of 15 mg/kg) cell kill was completely prevented by FCS. The serum did not contain thymidine (TdR) but had significant amounts of uridine (UR). When 5-FU was delivered in dialyzed FCS, concentrations of 50--100 micrograms/ml achieved only a modest 15% cell kill after 1 hour treatment. Regardless of medium supplement, the killing effect of 5-FU did not increase beyond concentrations greater than 2,000 micrograms/ml. Increasing the exposure interval dramatically increased the killing of LoVo cells by 5-FU, although the effects of medium supplement on the degree of cell survival persisted for about 12 hours. Virtually all of the incorporated 5-FU was transformed into 5-FUR, and a very small proportion eventually was incorporated into nucleic acids, suggesting that the killing effect of 5-FU on LoVo cells is mediated mostly by ribosidation and not by conversion into the deoxyribonucleoside. This conclusion is supported by the failure of 5-FUdR to kill LoVo cells after a treatment interval of one hour, even at concentrations of 5000 micrograms/ml; yet after the same exposure interval, 5-FUR effectively killed cells at concentrations of 50--100 micrograms/ml. TdR afforded no protection from cell kill by 5-FU. In contrast, UR was capable of protecting LoVo cells from the lethal effects of both 5-FU and 5-FUR even at concentrations as low as 10 micrograms/ml. Ftorafur exposed to LoVo cells for 1 hour had a slight killing effect (about 20--25%) at concentrations ranging up to 2000 micrograms/ml. Although the lethal effect of ftorafur was slightly increased after longer periods of incubation, it failed to reach 90% even after intervals of 48 hours. The results on cellular sensitivity that we obtained for LoVo cells treated with various fluorinated pyrimidines differ substantially from those of other investigators who used different methods to assess cell killing on nonhuman and noncolonic cell systems. The predictive relevance of these data as compared to those obtained in other systems is justified by the suboptimal results with these agents in clinical practice.
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