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Hsieh PH, Phal Y, Prasanth KV, Bhargava R. Cell Phase Identification in a Three-Dimensional Engineered Tumor Model by Infrared Spectroscopic Imaging. Anal Chem 2023; 95:3349-3357. [PMID: 36574385 PMCID: PMC10214899 DOI: 10.1021/acs.analchem.2c04554] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Cell cycle progression plays a vital role in regulating proliferation, metabolism, and apoptosis. Three-dimensional (3D) cell cultures have emerged as an important class of in vitro disease models, and incorporating the variation occurring from cell cycle progression in these systems is critical. Here, we report the use of Fourier transform infrared (FT-IR) spectroscopic imaging to identify subtle biochemical changes within cells, indicative of the G1/S and G2/M phases of the cell cycle. Following previous studies, we first synchronized samples from two-dimensional (2D) cell cultures, confirmed their states by flow cytometry and DNA quantification, and recorded spectra. We determined two critical wavenumbers (1059 and 1219 cm-1) as spectral indicators of the cell cycle for a set of isogenic breast cancer cell lines (MCF10AT series). These two simple spectral markers were then applied to distinguish cell cycle stages in a 3D cell culture model using four cell lines that represent the main stages of cancer progression from normal cells to metastatic disease. Temporal dependence of spectral biomarkers during acini maturation validated the hypothesis that the cells are more proliferative in the early stages of acini development; later stages of the culture showed stability in the overall composition but unique spatial differences in cells in the two phases. Altogether, this study presents a computational and quantitative approach for cell phase analysis in tissue-like 3D structures without any biomarker staining and provides a means to characterize the impact of the cell cycle on 3D biological systems and disease diagnostic studies using IR imaging.
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Affiliation(s)
- Pei-Hsuan Hsieh
- Department of Bioengineering and Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Yamuna Phal
- Department of Electrical and Computer Engineering and Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Kannanganattu V Prasanth
- Department of Cell and Developmental Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Rohit Bhargava
- Departments of Bioengineering, Electrical and Computer Engineering, Mechanical Science and Engineering, Chemical and Biomolecular Engineering, and Chemistry, Beckman Institute for Advanced Science and Technology, Cancer Center at Illinois, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
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2
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Villar-Argaiz M, López-Rodríguez MJ, Tierno de Figueroa JM. Divergent nucleic acid allocation in juvenile insects of different metamorphosis modes. Sci Rep 2021; 11:10313. [PMID: 33986401 PMCID: PMC8119467 DOI: 10.1038/s41598-021-89736-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Accepted: 04/19/2021] [Indexed: 12/05/2022] Open
Abstract
Nucleic acids help clarify variation in species richness of insects having different metamorphosis modes, a biological conundrum. Here we analyse nucleic acid contents of 639 specimens of aquatic insects collected from four high mountain streams of Sierra Nevada in southern Spain to test whether the allocation to RNA or DNA content differs during ontogeny between juvenile insects undergoing direct (hemimetabolous) or indirect (holometabolous) metamorphosis. The results show that RNA content as a function of body mass was negatively correlated to insect body length in four out of six and three out of six of the holometabolan and hemimetabolan taxa, respectively. Although no significant differences in RNA content were found between holometabolans and hemimetabolans, the significant interaction between body length and metamorphosis mode for RNA and RNA:DNA indicates a strong ontogenetic component to RNA allocation. In addition, our finding of lower DNA content in holometabolans relative to hemimetabolans agree with the analysis of empirical genome data in aquatic and terrestrial insects, and extend to this class of arthropods the “growth rate-genome size-nutrient limitation” hypothesis that differences in allocation between RNA and DNA may reflect fundamental evolutionary trade-off of life-history strategies associated with high growth rates (and RNA content) in holometabolans at the expense of diminished genome sizes.
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Affiliation(s)
- Manuel Villar-Argaiz
- Departamento de Ecología, Facultad de Ciencias, Universidad de Granada, 18071, Granada, Spain.
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3
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Abstract
Cell cycle cytometry and analysis are essential tools for studying cells of model organisms and natural populations (e.g., bone marrow). Methods have not changed much for many years. The simplest and most common protocol is DNA content analysis, which is extensively published and reviewed. The next most common protocol, 5-bromo-2-deoxyuridine S phase labeling detected by specific antibodies, is also well published and reviewed. More recently, S phase labeling using 5'-ethynyl-2'-deoxyuridine incorporation and a chemical reaction to label substituted DNA has been established as a basic, reliable protocol. Multiple antibody labeling to detect epitopes on cell cycle regulated proteins, which is what this chapter is about, is the most complex of these cytometric cell cycle assays, requiring knowledge of the chemistry of fixation, the biochemistry of antibody-antigen reactions, and spectral compensation. However, because this knowledge is relatively well presented methodologically in many papers and reviews, this chapter will present a minimal Methods section for one mammalian cell type and an extended Notes section, focusing on aspects that are problematic or not well described in the literature. Most of the presented work involves how to segment the data to produce a complete, progressive, and compartmentalized cell cycle analysis from early G1 to late mitosis (telophase). A more recent development, using fluorescent proteins fused with proteins or peptides that are degraded by ubiquitination during specific periods of the cell cycle, termed "Fucci" (fluorescent, ubiquitination-based cell cycle indicators) provide an analysis similar in concept to multiple antibody labeling, except in this case cells can be analyzed while living and transgenic organisms can be created to perform cell cycle analysis ex or in vivo (Sakaue-Sawano et al., Cell 132:487-498, 2007). This technology will not be discussed.
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Affiliation(s)
- James W Jacobberger
- Case Comprehensive Cancer Center, Case Western Reserve University, 10900 Euclid Ave., Cleveland, OH, 44106, USA.
| | - R Michael Sramkoski
- Case Comprehensive Cancer Center, Case Western Reserve University, 10900 Euclid Ave., Cleveland, OH, 44106, USA
| | - Tammy Stefan
- Case Comprehensive Cancer Center, Case Western Reserve University, 10900 Euclid Ave., Cleveland, OH, 44106, USA
| | - Philip G Woost
- Case Comprehensive Cancer Center, Case Western Reserve University, 10900 Euclid Ave., Cleveland, OH, 44106, USA
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4
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Zucchiatti P, Mitri E, Kenig S, Billè F, Kourousias G, Bedolla DE, Vaccari L. Contribution of Ribonucleic Acid (RNA) to the Fourier Transform Infrared (FTIR) Spectrum of Eukaryotic Cells. Anal Chem 2016; 88:12090-12098. [PMID: 28193045 DOI: 10.1021/acs.analchem.6b02744] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
We report on an optimized protocol for the digestion of cellular RNA, which minimally affects the cell membrane integrity, maintaining substantially unaltered the vibrational contributions of the other cellular macromolecules. The design of this protocol allowed us to collect the first Fourier transform infrared (FTIR) spectra of intact hydrated B16 mouse melanoma cells deprived of RNA and to highlight the in-cell diagnostic spectral features of it. Complementing the cellular results with the FTIR analysis of extracted RNA, ds-DNA, ss-cDNA and isolated nuclei, we verified that the spectral component centered at ∼1220 cm-1 is a good qualitative and semiquantitative marker of cellular DNA, since it is minimally affected by cellular RNA removal. Conversely, the band centered at ∼1240 cm-1, conventionally attributed to RNA, is only a qualitative marker of it, since its intensity is majorly influenced by other macromolecules containing diverse phosphate groups, such as phospholipids and phosphorylated proteins. On the other hand, we proved that the spectral contribution centered at ∼1120 cm-1 is the most reliable indicator of variations in cellular RNA levels, that better correlates with cellular metabolic activity. The achievement of these results have been made possible also by the implementation of new methods for baseline correction and automated peak fitting, presented in this paper.
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Affiliation(s)
- Paolo Zucchiatti
- Elettra-Sincrotrone Trieste, S.S. 14 Km 163.5, 34151, Trieste, Italy.,Dipartimento di Fisica, Università degli Studi di Trieste , via Valerio 2, 34127 Trieste, Italy
| | - Elisa Mitri
- Elettra-Sincrotrone Trieste, S.S. 14 Km 163.5, 34151, Trieste, Italy
| | - Saša Kenig
- Elettra-Sincrotrone Trieste, S.S. 14 Km 163.5, 34151, Trieste, Italy
| | - Fulvio Billè
- Elettra-Sincrotrone Trieste, S.S. 14 Km 163.5, 34151, Trieste, Italy
| | - George Kourousias
- Elettra-Sincrotrone Trieste, S.S. 14 Km 163.5, 34151, Trieste, Italy
| | - Diana Eva Bedolla
- Elettra-Sincrotrone Trieste, S.S. 14 Km 163.5, 34151, Trieste, Italy
| | - Lisa Vaccari
- Elettra-Sincrotrone Trieste, S.S. 14 Km 163.5, 34151, Trieste, Italy
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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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6
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Claro S, Oshiro MEM, Mortara RA, Paredes-Gamero EJ, Pereira GJS, Smaili SS, Ferreira AT. γ-Rays-generated ROS induce apoptosis via mitochondrial and cell cycle alteration in smooth muscle cells. Int J Radiat Biol 2014; 90:914-27. [DOI: 10.3109/09553002.2014.911988] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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7
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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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8
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Jiang J, Liu L, Li X, Tao D, Hu J, Qin J. Defining the restriction point in normal asynchronous human peripheral blood lymphocytes. Cytometry A 2013; 83:944-51. [PMID: 23926097 DOI: 10.1002/cyto.a.22341] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2013] [Revised: 06/27/2013] [Accepted: 06/28/2013] [Indexed: 11/10/2022]
Abstract
Although the restriction point (R-point) was proposed in animal cells several decades ago, its existence in normal cells is still controversial, because, in most studies, long-term cultured cell lines rather than primary normal cells were used. Furthermore, cell synchronization was generally applied, resulting in growth imbalance between DNA synthesis and protein expression in cells. Finally, R-point was originally proposed as a unique arrest point that may be in G0 phase; however, generally believed R-point locates within G1 phase. Thus, up to now, there is no solid experimental evidence that supports the existence of R-point in asynchronous primary normal cells. In this study, we used freshly purified peripheral human blood lymphocytes, as asynchronous primary normal cells, to confirm the existence of restriction point in G1 not G0 phase. Our findings may help uncover the mystery of the deregulation of cell cycle progression in malignant tumors. © 2013 International Society for Advancement of Cytometry.
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Affiliation(s)
- Jianwu Jiang
- Department of Surgery and Molecular Medical Center, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, People's Republic of China
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9
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Bedolla DE, Kenig S, Mitri E, Ferraris P, Marcello A, Grenci G, Vaccari L. Determination of cell cycle phases in live B16 melanoma cells using IRMS. Analyst 2013; 138:4015-21. [PMID: 23662303 DOI: 10.1039/c3an00318c] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The knowledge of cell cycle phase distribution is of paramount importance for understanding cellular behaviour under normal and stressed growth conditions. This task is usually assessed using Flow Cytometry (FC) or immunohistochemistry. Here we report on the use of FTIR microspectroscopy in Microfluidic Devices (MD-IRMS) as an alternative technique for studying cell cycle distribution in live cells. Asynchronous, S- and G0-synchronized B16 mouse melanoma cells were studied by running parallel experiments based on MD-IRMS and FC using Propidium Iodide (PI) staining. MD-IRMS experiments have been done using silicon-modified BaF2 devices, where the thin silicon layer prevents BaF2 dissolution without affecting the transparency of the material and therefore enabling a better assessment of the Phosphate I (PhI) and II (PhII) bands. Hierarchical Cluster Analysis (HCA) of cellular microspectra in the 1300-1000 cm(-1) region pointed out a distribution of cells among clusters, which is in good agreement with FC results among G0/G1, S and G2/M phases. The differentiation is mostly driven by the intensity of PhI and PhII bands. In particular, PhI almost doubles from the G0/G1 to G2/M phase, in agreement with the trend followed by nucleic acids during cellular progression. MD-IRMS is then proposed as a powerful method for the in situ determination of the cell cycle stage of an individual cell, without any labelling or staining, which gives the advantage of possibly monitoring specific cellular responses to several types of stimuli by clearly separating the spectral signatures related to the cellular response from those of cells that are normally progressing.
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Affiliation(s)
- Diana E Bedolla
- Elettra Sincrotrone Trieste, SISSI beamline, S.S. 14 Km 163.5, 34149 Basovizza, Trieste, Italy
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10
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Cheung MC, Evans JG, McKenna B, Ehrlich DJ. Deep ultraviolet mapping of intracellular protein and nucleic acid in femtograms per pixel. Cytometry A 2011; 79:920-32. [PMID: 21796773 PMCID: PMC3199293 DOI: 10.1002/cyto.a.21111] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2011] [Revised: 06/28/2011] [Accepted: 06/30/2011] [Indexed: 11/09/2022]
Abstract
By using imaging spectrophotometry with paired images in the 200- to 280-nm wavelength range, we have directly mapped intracellular nucleic acid and protein distributions across a population of Chinese hamster ovary (CHO-K1) cells. A broadband 100× objective with a numerical aperture of 1.2 NA (glycerin immersion) and a novel laser-induced-plasma point source generated high-contrast images with short (∼100 ms) exposures and a lateral resolution nearing 200 nm that easily resolves internal organelles. In a population of 420 CHO-K1 cells and 477 nuclei, we found a G1 whole-cell nucleic acid peak at 26.6 pg, a nuclear-isolated total nucleic acid peak at 11.4 pg, and, as inferred by RNase treatment, a G1 total DNA mass of 7.4 pg. At the G1 peak, we found a whole-cell protein mass of 95.6 pg, and a nuclear-isolated protein mass of 39.3 pg. An algorithm for protein quantification that senses peptide-bond (220-nm) absorbance was found to have a higher signal-to-noise ratio and to provide more reliable nucleic acid and protein determinations when compared to more classical 280/260-nm algorithms when used for intracellular mass mapping. Using simultaneous imaging with common nuclear stains (Hoechst 33342, Syto-14, and Sytox Orange), we have compared staining patterns to deep-UV images of condensed chromatin and have confirmed bias of these common nuclear stains related to nuclear packaging. The approach allows absolute mass measurements with no special sample preparation or staining. It can be used in conjunction with normal fluorescence microscopy and with relatively modest modification of the microscope.
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Affiliation(s)
- Man C Cheung
- Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA
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11
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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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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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Berman DM, Wincovitch S, Garfield S, Romeo MJ. Grading melanocytic dysplasia in paraffin wax embedded tissue by the nucleic acid index. J Clin Pathol 2006; 58:1206-10. [PMID: 16254113 PMCID: PMC1770753 DOI: 10.1136/jcp.2005.026559] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
BACKGROUND Although nucleic acid derangements are the hallmark of melanocytic dysplasia, the gold standard for its diagnosis remains the microscopic evaluation of haematoxylin and eosin stained slides. However, light microscopy is subjective and crucial genomic changes do not always show as changes in histology. AIMS To introduce the nucleic acid index (NAI) as a means of analysing nucleic acid derangements in histological sections at the level of the individual cell and within the context of its microenvironment. METHODS Confocal laser scanning microscopy was performed on melanocytic lesions stained with acridine orange (AO), a fluorescent stain for DNA and RNA. The NAI, calculated by measuring the fluorescence intensities of AO in nuclei relative to the surrounding cytoplasm, reflects the concentration of DNA relative to RNA. RESULTS When applied to benign naevi, dysplastic naevi, and melanoma, a very strong significant association was seen between lower NAI and malignant potential (p < 0.0001). Strong inverse correlations were found between NAI and both mitotic index and Breslow thickness. Interestingly, the NAI for dysplastic naevi is between that of melanoma and most benign naevi, consistent with their intermediate biological behaviour and histological appearance. CONCLUSION By providing a quantitative measure for melanocytic neoplasia, the NAI may improve the diagnosis of melanocytic lesions and the selection of treatment.
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Affiliation(s)
- D M Berman
- Laboratory of Pathology, National Cancer Institute, Bldg 10-2N212, 10 Center Drive Bethesda, MD 20896, USA.
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14
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Del Bino G, Darzynkiewicz Z, Degraef C, Mosselmans R, Fokan D, Galand P. Comparison of methods based on annexin-V binding, DNA content or TUNEL for evaluating cell death in HL-60 and adherent MCF-7 cells. Cell Prolif 1999. [PMID: 10371301 DOI: 10.1046/j.1365-2184.1999.3210025.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
HL-60 and MCF-7 cells were treated with 0.15 microM camptothecin (CPT) or with the solvent dimethylsulfoxide (DMSO) for the controls, for 2, 3 and 4 h or for 24, 48 and 72 h, respectively. The apoptotic index (AI) was then evaluated in parallel by the following flow cytometric methods: (1) double staining of unfixed cells with fluoresceinated annexin V and propidium iodide (PI), this after detachment by trypsinization in the case of MCF-7 cultures; (2) prefixation in 70% ethanol, extraction of degraded, low molecular weight DNA with 0.2 M phosphatecitrate buffer and analysis of the DNA content stained with PI; (3) TUNEL, i.e. labelling of DNA strand breaks with biotin-dUTP, followed by staining with streptavidin-fluorescein and counterstaining with PI. In HL-60 cells, the three methods gave similar results for the AI (3-4% in the controls and at 2 h of CPT treatment, and 35-43% at 3 and 4 h after CPT). This indicates that CPT-induced membrane alteration and DNA fragmentation occurred concomitantly in those cells. For MCF-7 cells, CPT-induced apoptosis developed more slowly, the AI, whether based on annexin V or on DNA content, remained unchanged at 24 h, then was increasing to 8% at 48 h and to 25% at 72 h of treatment. In these cells, the TUNEL index did not increase prior to 72 h, and the increase was minor (up to 9% vs. 2-3% in the controls) at 72 h of the treatment. This indicates that in MCF-7 cells DNA strand breaks cannot be effectively labelled, which may be due to inaccessibility of 3'-OH ends in the breaks to exogenous terminal deoxynucleotidyl transferase. The mechanism of endonucleolytic DNA fragmentation thus may be different, depending on the cell type.
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Affiliation(s)
- G Del Bino
- Laboratory for Cytology and Experimental Oncology, Faculty of Medicine, Free University of Brussels (ULB), Belgium
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15
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Erba E, Sen S. Synchronization of cancer cell lines with methotrexate in vitro. ACTA ACUST UNITED AC 1996. [DOI: 10.1007/bf00122166] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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16
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Barque JP, Abahamid A, Bourezgui Y, Chacun H, Bonaly J. Growth responses of achlorophyllous Euglena gracilis to selected concentrations of cadmium and pentachlorophenol. ARCHIVES OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 1995; 28:8-12. [PMID: 7717763 DOI: 10.1007/bf00213962] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
The growth response of a wild achlorophyllous Euglena gracilis mutant was studied during exposure to cadmium and pentachlorophenol (PCP). Cadmium gradually reduced the growth rate and terminal cell density; PCP only lengthened the initial lag phase relative to control cultures. Flow cytometry showed that cadmium altered the cell cycle by delaying late S and G2/M phases; PCP did not disturb the cell cycle, but markedly affected DNA staining: the intercalating dyes ethidium bromide and propidium iodide showed little staining compared to controls. However, replication and transcription processes were not altered by PCP, as cell division occurred normally. Cells surviving after PCP treatment apparently developed an adaptative response during the lag phase.
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Affiliation(s)
- J P Barque
- Laboratoire de Métabolisme Cellulaire et Xénobiotiques, Faculté de Pharmacie, Chatenay-Malabry, France
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17
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Traganos F, Gong J, Ardelt B, Darzynkiewicz Z. Effect of staurosporine on MOLT-4 cell progression through G2 and on cytokinesis. J Cell Physiol 1994; 158:535-44. [PMID: 8126077 DOI: 10.1002/jcp.1041580320] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Staurosporine (SSP) is an inhibitor of a variety of protein kinases with an especially high affinity towards protein kinase C. Whereas SSP has been shown to halt the cell cycle progression of various normal, nontransformed cell types in G1, most virus transformed or tumor cells are unaffected in G1 but arrest in G2 phase. SSP has also been observed to increase the appearance of cells with higher DNA content, suggestive of endoreduplication, in cultures of tumor cells. Using multivariate flow cytometry (DNA content vs. expression of cyclin B, nuclear p120 protein, or protein reactive with Ki-67 antibody) which makes it possible to discriminate cells with identical DNA content but at different phases of the cycle, we have studied the cell cycle progression of human lymphocytic leukemic MOLT-4 cells in the presence of 0.1 microM SSP. MOLT-4 cells did not arrest in G1 or G2 phase in the presence of the inhibitor. Rather, they failed to undergo cytokinesis, entering G1 phase at higher DNA ploidy (tetraploidy; G1T), and then progressed through ST (rereplication) into G2T and MT. The rates of entrance to G2 and G2T were essentially identical, indicating that the rates of cell progression through S and ST as well as through G2 and G2T, respectively, were similar. Cells entrance to mitosis and mitotic chromatin condensation were also similar at the diploid and tetraploid DNA content level and were unaffected by 0.1 microM SSP. No evidence of growth imbalance (altered protein or RNA to DNA ratio) was observed in the case of tetraploid cells. The data show that, in the case of MOLT-4 cells, all events associated with the chromosome or DNA cycle were unaffected by SSP; the only target of the inhibitor appears to be kinase(s) controlling cytokinesis.
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Affiliation(s)
- F Traganos
- Cancer Research Institute, New York Medical College, Elmsford 10523
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18
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Affiliation(s)
- Z Darzynkiewicz
- Cancer Research Institute, New York Medical College, Valhalla 10595
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19
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Takahashi K, Tereda S, Ueda H, Makishima F, Suzuki E. Growth rate suppression of cultured mammalian cells enhances protein productivity. Cytotechnology 1994; 15:57-64. [PMID: 7765953 DOI: 10.1007/bf00762379] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Suppression of proliferation of cells which contain stable or stabilized mRNA coded for a protein to be produced, a partial mimic of cell differentiation, was examined for enhancing protein production by cultured mammalian cells. Hybridoma 2E3 cells which were adapted to be interleukin-6 sensitivity growth-suppressed accumulated the mRNA of IgG1 which is reported stable, and IgG1 production rate increased as a result when their growth was suppressed with interleukin-6. A myeloma cell line was similarly adapted; the obtained myeloma cells can be used as host cells for enhancing production of exogenous proteins by suppressing growth with interleukin-6. Temperature-sensitively growth-suppressible mutants of mouse mammary carcinoma FM3A were transfected with cDNA of IgM lambda 1 chain and cultured at nonpermissive temperature to enhance production of lambda 1. Addition of various growth-suppressive reagents to culture medium was studied for finding methods suitable for suppressing growth while maintaining high cell viability. Caffeine yielded the best results among these reagents. Deprivation of various growth-supporting components in culture medium was also tested; simultaneous deprivation of insulin and transferrin viably suppressed growth of hybridoma 2E3 cells, resulting in enhanced antibody productivity.
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Affiliation(s)
- K Takahashi
- Department of Chemistry and Biotechnology, Faculty of Engineering, University of Tokyo, Japan
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20
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Weller EM, Poot M, Hoehn H. Induction of replicative senescence by 5-azacytidine: fundamental cell kinetic differences between human diploid fibroblasts and NIH-3T3 cells. Cell Prolif 1993; 26:45-54. [PMID: 7679929 DOI: 10.1111/j.1365-2184.1993.tb00005.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
To analyse the putative role of methylation of cytosine residues in the nuclear DNA as a regulatory step during cellular ageing, we incubated ageing human amniotic fluid derived fibroblast-like cells and non-ageing NIH-3T3 cells with 5-azacytidine. BrdUrd/Hoechst and acridine orange (AO) flow cytometry was used to compare the effects of the base analogue on cell proliferation and cell differentiation. In NIH-3T3 cultures, 96h exposures to 4 microM 5-azacytidine caused diminished cell proliferation due to cell arrest in the G1 compartments of the second and third cell cycles of serum stimulated cells. The exit from the G0/G1 compartment was not affected. The 5-azacytidine induced cell kinetic disturbances were unstable in NIH-3T3 cultures, such that pre-treated cells reverted to normal cell cycle transit within 2-3 days after termination of treatment. In contrast, 5-azacytidine pre-treated amniotic fluid derived fibroblast-like cell cultures showed persistently elevated G2 phase arrests and delayed G0/G1 phase exit kinetics, which explain the premature cessation of proliferation observed in these primary cultures. In both cell systems, 5-azacytidine exposed cultures showed elevated numbers of G1 phase cells with increased RNA content as revealed by AO flow cytometry. Again, this effect was reversible in NIH-3T3 cells but not in amniotic fluid derived fibroblast-like cells. These contrasting responses to 5-azacytidine are likely to reflect intrinsic differences in methylation patterns or de novo methylase activity between ageing cell strains and non-ageing cell lines.
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Affiliation(s)
- E M Weller
- Department of Human Genetics, University of Würzburg, Germany
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21
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Zucker RM, Adams DJ, Bair KW, Elstein KH. Polyploidy induction as a consequence of topoisomerase inhibition. A flow cytometric assessment. Biochem Pharmacol 1991; 42:2199-208. [PMID: 1659821 DOI: 10.1016/0006-2952(91)90357-b] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Following recovery from a 4-hr exposure to clinically achievable concentrations of the topoisomerase II inhibitors Adriamycin, teniposide, or amsacrine or the putative topoisomerase II inhibitor crisnatol, murine erythroleukemic cells remained viable for up to 48 hr, but did not proliferate. Cell cycle analysis after a 24-hr recovery revealed blocks in G2 (4N DNA) or greater than G2 (up to 8N DNA) polyploid stages. The relative percentages of cells in either stage was a function of drug concentration and cell cycle stage at time of exposure: typically, cells exposed during S phase became blocked in G2, whereas those exposed during G2/M progressed into greater than G2 polyploid stages. G2-blocked cells exhibited a 2- to 3-fold increase in nuclear protein content and cellular/nuclear volume (i.e. unbalanced growth) and approximately 5% more DNA stainability (as a consequence of nuclear conformational changes rather than redundant DNA synthesis). In all cases, at the drug concentrations studied, mitotic figures were absent and G2 and greater than G2 blocks were irreversible, indicating that the mechanism of polyploidy induction differs from that of microtubule inhibitors. These findings suggest that although topoisomerase inhibitors interfere with DNA synthesis in the S phase, their induction of greater than G2 polyploid blocks may involve direct or indirect inhibition of chromosome condensation.
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Affiliation(s)
- R M Zucker
- ManTech Environmental Technology, Inc., Research Triangle Park, NC 27709
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22
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23
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Jakóbisiak M, Bruno S, Skierski JS, Darzynkiewicz Z. Cell cycle-specific effects of lovastatin. Proc Natl Acad Sci U S A 1991; 88:3628-32. [PMID: 1673788 PMCID: PMC51505 DOI: 10.1073/pnas.88.9.3628] [Citation(s) in RCA: 208] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Lovastatin (LOV), the drug recently introduced to treat hypercholesteremia, inhibits the synthesis of mevalonic acid. The effects of LOV on the cell cycle progression of the human bladder carcinoma T24 cell line expressing activated p21ras were investigated. At a concentration of 2-10 microM, LOV arrested cells in G1 and also prolonged--or arrested a minor fraction of cells in--the G2 phase of the cell cycle; at a concentration of 50 microM, LOV was cytotoxic. The cytostatic effects were reversed by addition of exogenous mevalonate. Cells arrested in the cycle by LOV were viable for up to 72 hr and did not show any changes in RNA or protein content or chromatin condensation, which would be typical of either unbalanced growth or deep quiescence. The expression of the proliferation-associated nuclear proteins Ki-67 and p105 in these cells was reduced by up to 72% and 74%, respectively, compared with exponentially growing control cells. After removal of LOV, the cells resumed progression through the cycle; they entered S phase asynchronously after a lag of approximately 6 hr. Because mevalonate is essential for the posttranslational modification (isoprenylation) of p21ras, which in turn allows this protein to become attached to the cell membrane, the data suggest that the LOV-induced G1 arrest may be a consequence of the loss of the signal transduction capacity of p21ras. Indeed, while exposure of cells to LOV had no effect on the cellular content of p21ras (detected immunocytochemically), it altered the intracellular location of this protein, causing its dissociation from the cell membrane and translocation toward the cytoplasm and nucleus. However, it is also possible that inhibition of isoprenylation of proteins other than p21ras (e.g., nuclear lamins) by LOV may be responsible for the observed suppression of growth of T24 cells.
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Affiliation(s)
- M Jakóbisiak
- Sloan-Kettering Institute for Cancer Research, New York, NY 10021
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24
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Henderson GI, Baskin GS, Frosto TA, Schenker S. Interactive effects of ethanol and caffeine on rat fetal hepatocyte replication and EGF receptor expression. Alcohol Clin Exp Res 1991; 15:175-80. [PMID: 2058791 DOI: 10.1111/j.1530-0277.1991.tb01850.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
This study reports on the interactive effects of ethanol and caffeine on growth of rat fetal hepatocytes. Exposure of cultured rat fetal hepatocytes (RFH) to ethanol in concentrations above 1 mg/ml, causes a blockade of EGF-dependent cell replication along with an overexpression of surface EGF receptors (EGF-R). However, RFHs exposed for 24 hours to ethanol at a concentration of 1 mg/ml alone had little effect on cell replication. Caffeine, when combined with this concentration of alcohol, progressively impaired RFH growth by up to 100%. Caffeine alone up to 10 micrograms/ml, on the other hand, caused a progressive increase in RFH replication associated with a 69% enhancement of DNA synthesis. Caffeine concentrations in excess of 50 micrograms/ml had no effect on replicative capacity. Concomitant caffeine exposure had no effect on the ethanol-related increase in cell DNA content, yet it caused a further enhancement of the cell protein accural induced by ethanol alone. Caffeine (10 micrograms/ml) alone had no effect on EGF-R expression, while ethanol (2 mg/ml) increased it by almost 200%. Addition of caffeine to ethanol reduced this enhanced EGF binding by 45%. Scatchard analysis indicated that no treatment altered ligand affinity for the receptor, but that the alterations in binding caused by ethanol and the caffeine/ethanol combination reflected changes in binding capacity, in both low and high affinity components. It is concluded that (1) ethanol blocks EGF-mediated replication accompanied by a reduction in DNA synthesis, (2) caffeine alone at low concentrations has the opposite effect and can actually potentiate the EGF-mediated mitogenic response, (3) caffeine in combination with ethanol acts synergistically to reduce RFH replication.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- G I Henderson
- Department of Medicine, University of Texas Health Science Center, San Antonio 78284-7878
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25
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Abstract
The DNA topoisomerase I inhibitor camptothecin (CAM) is selectively cytotoxic to S-phase cells of HL-60, and some other myelogenous leukemic lines. The early effects of cell exposure to 0.05-0.2 micrograms/ml CAM are seen after 2 h; at that time a progressive degradation of DNA in the chromatin of S-phase cells is initiated. The degradation manifests by "pulverization" of chromatin followed by coalescence of the fine granules and nuclear disintegration. Between 2 and 6 h of treatment, a loss of about 30-70% of DNA from S-phase nuclei is detected by flow cytometry. A 10-min pulse of CAM is adequate to trigger subsequent DNA degradation. Agarose gel electrophoresis of DNA from CAM-treated cells reveals a typical nucleosome core particles "ladder," suggestive of preferential degradation of spacer DNA. Despite extensive loss of DNA and nuclear disintegration, the cell membrane of CAM-treated S-phase cells remains intact for several hours, excluding trypan blue or propidium iodide. Mitochondria, assayed for their ability to maintain a transmembrane potential (rhodamine 123 retention), as well as the lysosomal proton pump (probed by supravital uptake of acridine orange) also remain unchanged in these cells. G1 cells are refractory to CAM under these conditions. Synchronization of cells in S phase by aphidicolin increases the sensitivity of the whole cell population to CAM. The data suggest that CAM or other topoisomerase I inhibitors may be effective in some myelogenous leukemias, especially in combination with treatments synchronizing cells in S phase.
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26
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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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27
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Sen S, Erba E, D'Incalci M. Synchronisation of cancer cell lines of human origin using methotrexate. CYTOMETRY 1990; 11:595-602. [PMID: 2379450 DOI: 10.1002/cyto.990110506] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
U937 human histiocytic lymphoma cell line and SW626 ovarian carcinoma line of human origin were synchronised using very low, nontoxic concentrations (0.04-0.08 microM for 16-24 h) of methotrexate (MTX) under standard culture conditions. Satisfactory synchrony was achieved to study S phase events. Various kinetic behaviours and biological properties of the synchronised cells are considered for characterisation of the system. MTX-synchronisation was compared with that induced by aphidicolin (APC) alone and by serum deprivation and APC. In some cancer cell lines MTX appears to be the best choice for obtaining highly synchronised cell populations without cytotoxicity or physiological perturbations.
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Affiliation(s)
- S Sen
- Istituto di Ricerche Farmacologiche Mario Negri, Milano, Italy
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28
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Traganos F, Kimmel M, Bueti C, Darzynkiewicz Z. Effects of inhibition of RNA or protein synthesis on CHO cell cycle progression. J Cell Physiol 1987; 133:277-87. [PMID: 2445763 DOI: 10.1002/jcp.1041330211] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Chinese hamster ovary (CHO) cells, synchronized by selective detachment at mitosis, were treated with various concentrations of actinomycin D (AMD) or cycloheximide (CHX) either immediately, or 1, 2, or 3 hr after mitosis. Since the minimum duration of G1 phase in these cultures was 3.4 hr, the addition of RNA or protein synthesis inhibitors took place at the beginning, first third, second third, or end (G1-S boundary) of G1 phase. The kinetics of exit from G1 phase, the rate and extent of traverse of S phase, and the reaccumulation of RNA were estimated under each set of growth conditions by flow cytometry of acridine orange-stained cells. A mathematical model was constructed to describe the trajectories of the cell populations with respect to their increase in RNA and DNA content in the absence or presence of the inhibitor. The chronologic synchrony imposed on the CHO cell population began to decay within 3 hr, resulting in stochastic entrance of cells into S phase in the absence of inhibitor. Addition of AMD or CHX at 0, 1, 2, or 3 hr after mitosis, regardless of the inhibitor concentration, did not provide evidence of a critical restriction point in G1 beyond which cells were committed to enter S phase and were no longer sensitive to moderate suppression of RNA or protein synthesis. The observed kinetics of cell entrance into an traverse of S phase were consistent with an inherently heterogeneous response to serum stimulation occurring at or just after cell division.
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Affiliation(s)
- F Traganos
- Laboratory of Investigative Cytology, Memorial Sloan-Kettering Cancer Center, New York, New York 10021
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29
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Kimmel M, Traganos F. Kinetic Analysis of Drug-Induced G 2Block In Vitro. Cell Prolif 1985. [DOI: 10.1111/j.1365-2184.1985.tb00635.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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Kimmel M, Darzynkiewicz Z, Arino O, Traganos F. Analysis of a cell cycle model based on unequal division of metabolic constituents to daughter cells during cytokinesis. J Theor Biol 1984; 110:637-64. [PMID: 6084152 DOI: 10.1016/s0022-5193(84)80149-6] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
We demonstrate that the unequal division of RNA during cytokinesis explains the dispersion of cell generation times in CHO cell cultures. Experimental cytometric results reported previously serve as a basis for a probabilistic model of cytokinesis. Unequal RNA division to daughter cells, together with two simple laws of RNA production, are used as a source of randomness within the cell cycle. The model reproduces the experimental growth of the CHO cell population, including the observed variability in RNA content. The model has stabilizing properties which explain why a cell population with increased RNA content characteristics, a few cell cycles, to the original pattern. Other cell cycle characteristics, like sister-to-sister and mother-to-daughter generation time correlations implied by the model, are close to their experimental analogs. The conceptual basis of the model is general enough to include unequal division of factors other than RNA (cell mass, cell proteins, etc.) as sources of generation time variability. It seems that the observed dispersion of cell generation times, explained previously in the terms of random transitions in some part of the cell cycle (the Smith & Martin A and B state hypothesis), can be reduced to the single random event of unequal division. This supplies a new convenient tool in the investigation of cell cycle kinetics.
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Traganos F, Darzynkiewicz Z, Bueti C, Melamed MR. Effects of a prospective antitumor agent, 1,4-bis(2'-chloroethyl)-1,4-diazabicyclo-[2.2.1] heptane diperchlorate, on cultured mammalian cells. Cancer Invest 1984; 2:1-13. [PMID: 6584191 DOI: 10.3109/07357908409020281] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The effects of 1,4-bis(2'-chloroethyl)-1,4-diazabicyclo-[2.2.1] heptane diperchlorate (CBH; NSC 57198) on cell viability, growth, progression through the cell cycle, survival, and differentiation were investigated in suspension cultures of murine lymphocytic leukemia (L1210) and erythroleukemic (FL) cells and normal human lymphocytes stimulated with phytohemagglutinin (PHA) and in adherent cultures of Chinese hamster ovary (CHO) cells. CBH was equally cytotoxic toward stationary and exponentially growing CHO cells. Cell viability was diminished by 50% following 24 hr exposure to approximately 50 micrograms CBH per ml. Treatment of quiescent human lymphocytes for 24 hr with up to 100 micrograms CBH per ml did not appreciably diminish cell viability though the subsequent stimulation of such lymphocytes with PHA was inhibited in a dose dependent fashion. L1210, FL cells, and PHA stimulated human lymphocytes were equally sensitive to CBH, 50% inhibition of growth was obtained following 24 hr treatment with 25 micrograms CBH per ml. Incubation for up to 48 hr with CBH did not result in differentiation of FL cells to mature hemoglobin containing cells. Constant exposure of L1210 cells and PHA-stimulated human lymphocytes to 10-50 micrograms CBH per ml resulted in accumulation of cells in G2 + M phase; higher drug concentrations resulted in cell arrest in mid to late S phase and G2 phase. A short 1-hr pulse of the drug resulted in a transient accumulation of L1210 cells in S and G2 phases. However, cells recovered from a short pulse of drug and by 48 hr, both cell proliferation and the cell cycle distribution appeared normal. A detailed analysis of cell cycle progression of L1210 cells in the presence of the drug indicated that the duration of G2 phase was extended at low concentrations (10 micrograms/ml) while the transit of cells through S was retarded with subsequent accumulation in late S and G2 phase at higher (50 micrograms/ml) concentrations. Concomitant with cell arrest in S and G2 phase an increase in cellular RNA content indicating unbalanced growth was observed. This state of unbalanced growth was reversible in cultures exposed to a 1-hr pulse of up to 100 micrograms CBH per ml; cellular RNA content returned to control values by 48 hr. No effect on nuclear chromatin as assayed by acid denaturation was observed. Though the exact mechanism of drug action is not known, the data are not incompatible with the drug acting as an alkylating agent.
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Traganos F. Dihydroxyanthraquinone and related bis(substituted) aminoanthraquinones: a novel class of antitumor agents. Pharmacol Ther 1983; 22:199-214. [PMID: 6361801 DOI: 10.1016/0163-7258(83)90004-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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