51
|
Seyschab H, Friedl R, Schindler D, Hoehn H, Rabinovitch PS, Chen U. The effects of bacterial lipopolysaccharide, anti-receptor antibodies and recombinant interferon on mouse B cell cycle progression using 5-bromo-2'-deoxyuridine/Hoechst 33258 dye flow cytometry. Eur J Immunol 1989; 19:1605-12. [PMID: 2477251 DOI: 10.1002/eji.1830190913] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Polyclonal stimulation of resting B cells with anti-antigen receptor antibodies [anti-IgM mu chain antibody (anti-mu)] or with bacterial lipopolysaccharide (LPS) stimulates a proportion of B cells to proliferate. Exposure of resting B cells to both LPS and anti-mu activates a larger population of resting B cells than either alone, suggesting a synergistic effect of these two stimuli. Although recombinant interferon (rIFN) either alone or in combination with anti-mu has no apparent proliferative activity (as measured by [3H]thymidine incorporation), application of 5-bromo-2'-deoxyuridine/Hoechst 33258 dye flow cytometry reveals a distinct effect of rIFN on B cell growth. In the presence of anti-mu plus LPS, rIFN causes the majority of B cells to enter the cell cycle (CC), but a subset of B cells remains in the resting stage. Another subset of B cells has extremely rapid CC transit times, with a CC duration of less than 10 h. These studies show that both anti-mu and LPS are competence factors (which move cells from the G0 phase to the G1 phase). LPS acts also as a CC progression factor, while rIFN is a CC potentiating factor.
Collapse
|
52
|
Abstract
Elevated oxygen concentrations and paraquat, a superoxide-generating compound, induce an arrest of cells in the G2 phase of the cell cycle, which can be enhanced by adding bromodeoxyuridine (BrdU) to the culture medium. Experiments with the lipophilic peroxide cumene hydroperoxide and the free-radical scavenger vitamin E demonstrate that the BrdU-dependent G2 arrest is not mediated by lipid peroxidation. The BrdU-dependency of arrest in the G2 phase can be used as a sensitive cell biological assay to detect DNA damage elicited by oxygen free radicals.
Collapse
|
53
|
Poot M, Schmitt H, Seyschab H, Koehler J, Chen U, Kaempf U, Kubbies M, Schindler D, Rabinovitch PS, Hoehn H. Continuous bromodeoxyuridine labeling and bivariate ethidium bromide/Hoechst flow cytometry in cell kinetics. CYTOMETRY 1989; 10:222-6. [PMID: 2469558 DOI: 10.1002/cyto.990100215] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Most techniques of flow cytometric cell cycle analysis are not capable of distinguishing the number of rounds of DNA synthesis that a cell has undergone since the start of an experiment. Continuous labeling with 5-bromodeoxyuridine (BrdUrd) offers such a potential. We illustrate here that the bivariate analysis of non-BrdUrd-quenched ethidium bromide vs. BrdUrd-quenched Hoechst 33258 fluorescence offers a high degree of resolution that enhances the analytical power of the technique, and that this approach can be applied to the analysis of a broad range of human and murine primary cells and established cell lines.
Collapse
|
54
|
Poot M, Hoehn H, Nicotera TM, Rüdiger HW. Cell kinetic evidence suggests elevated oxidative stress in cultured cells of Bloom's syndrome. FREE RADICAL RESEARCH COMMUNICATIONS 1989; 7:179-87. [PMID: 2479595 DOI: 10.3109/10715768909087940] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Bromodeoxyuridine/Hoechst flow cytometry was used to analyse disturbed cell proliferation of fibroblasts and lymphoblastoid cells from Bloom's syndrome (BS). Fibroblasts show poor activation, arrest in the G2 phase of the cell cycle along with a prolongation of the G1 phase. This pattern of perturbed cells proliferation is akin to that elicited in normal fibroblasts by 4-hydroxy-nonenal, a breakdown product of lipid peroxides. Treatment with vitamin E improved growth of BS fibroblasts more strongly than growth of normal fibroblasts. Lymphoblastoid cells from BS, to the contrary, experience only a minor arrest in the G2 phase after one round of bromodeoxyuridine incorporation, but are strongly inhibited during and after the second S phase. Thus, their cell cycle arrest is dependent upon BrdU incorporation, as has been found previously in normal cells exposed to elevated concentrations of oxygen or paraquat, a superoxide generating compound. These results suggest that BS cells may suffer from an elevated, endogenous generation of oxygen free radicals.
Collapse
|
55
|
Poot M, Rabinovitch PS, Hoehn H. Free radical mediated cytotoxicity of desferrioxamine. FREE RADICAL RESEARCH COMMUNICATIONS 1989; 6:323-8. [PMID: 2477312 DOI: 10.3109/10715768909055158] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Toxic effects of desferrioxamine (DFO) upon cell growth were assayed with continuous bromodeoxyuridine (BrdU) labeling and bivariate ethidium bromide/Hoechst 33258 flow cytometry. At 5% oxygen DFO caused a dose-dependent inhibition of cell growth, which was potentiated at 20% oxygen, and by cumene hydroperoxide but not by paraquat. An irreversible arrest in the G2 phase of the cell cycle was the cell-kinetic mechanism underlying this growth inhibition. The G2 arrest was not dependent upon the BrdU concentration in the medium, thus ruling out a direct attack of a free radical on thymidine residues. The observed cytotoxicity of DFO cautions against its use in the treatment of conditions of elevated oxidative stress.
Collapse
|
56
|
Poot M, Esterbauer H, Rabinovitch PS, Hoehn H. Disturbance of cell proliferation by two model compounds of lipid peroxidation contradicts causative role in proliferative senescence. J Cell Physiol 1988; 137:421-9. [PMID: 3192623 DOI: 10.1002/jcp.1041370305] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Cumene hydroperoxide (Chp), a lipophilic peroxide, and hydroxy-nonenal (HNE), a breakdown product of lipid peroxides, were used as model compounds to assess the effects of lipid peroxidation upon cell proliferation. Amniotic fluid fibroblastlike (AFFL) cells and human diploid skin-derived (HDFL) cells were cultured with the two model compounds and cell proliferation was assayed via bromodeoxyuridine-Hoechst flow cytometry. At low doses Chp elicited an accumulation of cells in the S and G2 phase, while at higher doses the fraction of nonproliferating cells increased as well. Low doses of HNE caused an accumulation of cells in the G1 and G2 phase, whereas an additional increase of cells in S phase and in the nonproliferating fraction was found at an elevated concentration. A delay of onset of proliferation was obtained with both Chp and HNE. Permanent arrests in the S, G2, and G1 compartment are provoked by Chp only when Chp was applied together with serum. HNE, to the contrary, elicited a permanent arrest in the G2 and the G1 compartment even if added to quiescent cell cultures. Additionally, HNE caused a combination of a prolongation of the G1 phase of the cell cycle and an arrest in this compartment, which is reminiscent of cell differentiation. HDFL cells were much more sensitive toward Chp than were AFFL cells, but both cell types showed similar sensitivities toward HNE. We conclude that lipophilic peroxides exert toxic effects upon cell proliferation distinct from the pattern elicited by aldehydic breakdown products of lipid peroxides. The pattern of cell cycle arrest induced by Chp and HNE makes it unlikely that Chp and HNE, or related products of lipid peroxidation, are responsible for the limitation of the proliferative life span of human fibroblasts in culture.
Collapse
|
57
|
Schindler D, Hoehn H. Fanconi anemia mutation causes cellular susceptibility to ambient oxygen. Am J Hum Genet 1988; 43:429-35. [PMID: 3177386 PMCID: PMC1715501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
The gene defect causing the Fanconi anemia (FA) phenotype appears to be expressed at the cellular level, since FA fibroblasts show a protracted course of explant outgrowth, a diminished in vitro life span, and very poor cloning. We show that exposure of FA fibroblasts to hypoxic (5% v/v oxygen) culture conditions restores their growth in vitro to near normal. Exposure to elevated oxygen tension (35% v/v) causes accumulations of FA cells in the S and G2/M phases of the cell cycle that are in significant excess of those seen in heterozygote and control strains. In the absence of evidence for defective cytoplasmatic radical scavenging systems, these observations suggest increased nuclear susceptibility to ambient oxygen as cause of the FA cellular phenotype.
Collapse
|
58
|
Schindler D, Kubbies M, Priest RE, Hoehn H, Rabinovitch PS. The phytohemagglutinin response of human peripheral blood lymphocytes as a function of donor age: a re-examination using BrdU-Hoechst flow cytometry. Mech Ageing Dev 1988; 44:253-63. [PMID: 3216722 DOI: 10.1016/0047-6374(88)90026-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Mononuclear cells were isolated from peripheral blood by a standard Ficoll-Hypaque technique from 127 healthy donors, ranging in age from newborns to 86 years of age. As a measure of their in vitro growth response, the fraction of non-cycling cells was determined at 48 and 72 h after phytohemagglutinin (PHA) exposure by means of BrdU-Hoechst flow cytometry. This technique provides an optimal assay system for the non-cycling cell fraction, since all cycling cells will have incorporated BrdU thereby quenching the fluorescence of the Hoechst 33258 fluorochrome. Lymphocytes from prepubertal donors showed significantly decreased non-cycling cell fractions, as did lymphocytes from an additional group of 14 adults with hypogonadism due to the 45, XO condition (Turner-Syndrome). Much to our surprise, we found no definitive correlation between donor age and the non-cycling fraction of cells from the adult lymphocyte donors. Nor did we find any age-related increase in the variance of the non-cycling cell fraction. These observations suggest that the previously reported age-related decline in the PHA response of human PBL may reflect an increasing delay, rather than an overall diminution, of the PHA response as a function of donor age.
Collapse
|
59
|
Heckl W, Köhler J, Hoehn H, Dämmrich J. Characterization of a Newly Established Human Urinary Bladder Cancer Cell Line (BT-1). J Urol 1988. [DOI: 10.1016/s0022-5347(17)41536-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
|
60
|
Poot M, Schindler D, Kubbies M, Hoehn H, Rabinovitch PS. Bromodeoxyuridine amplifies the inhibitory effect of oxygen on cell proliferation. CYTOMETRY 1988; 9:332-8. [PMID: 2456899 DOI: 10.1002/cyto.990090410] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The BrdUrd-Hoechst method was used to analyze the interaction of various oxygen concentrations with BrdUrd substituted DNA with respect to cellular proliferation. At oxygen concentrations above 5%, human diploid fibroblast-like cells and amniotic fluid fibroblast-like cells showed reduced proliferation rates, which resulted from an increase in noncycling cells and from a permanent arrest of cells in the G2 phase of the cell cycle. At 35% oxygen the increase in noncyling cell fraction and the permanent arrest in G2 was strongly dependent upon the concentration of BrdUrd. Incorporation of BrdUrd into DNA, therefore, amplifies the adverse effects of increasing oxygen concentrations upon cell proliferation. The mechanism of this amplification might involve a free radical attack on DNA similar to the radiation sensitizing effect of BrdUrd.
Collapse
|
61
|
Rabinovitch PS, Kubbies M, Chen YC, Schindler D, Hoehn H. BrdU-Hoechst flow cytometry: a unique tool for quantitative cell cycle analysis. Exp Cell Res 1988; 174:309-18. [PMID: 2448151 DOI: 10.1016/0014-4827(88)90302-3] [Citation(s) in RCA: 118] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Unlike other techniques, flow cytometric analysis of BrdU-quenched 33258 Hoechst fluorescence may be used to measure cell activation and the G1, S, and G2/M compartment distributions in each of three successive cell cycles after growth stimulation of human peripheral blood lymphocytes. Cell cycle kinetic curves can be constructed from the BrdU-Hoechst flow data which allow the simultaneous assessment of growth fraction, lag-time, compartment exit rate, compartment duration, and compartment arrest. Applications of this new versatile technique include the evaluation of drug and growth factor effects, cell aging, and diagnosis in medicine and immunology.
Collapse
|
62
|
Heckl W, Köhler J, Hoehn H, Dämmrich J. Characterization of a newly established human urinary bladder cancer cell line (BT-1). UROLOGICAL RESEARCH 1988; 16:23-9. [PMID: 3344562 DOI: 10.1007/bf00264624] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
A new human transitonal cell carcinoma cell line has been established in long term tissue culture. The BT-1 cells were derived from a poorly differentiated human bladder cancer. The tumor cell line produces tumors in nude mice. BT-1 has been characterized by cytogenetic and flow cytometric analysis and by isoenzyme typing. As in direct preparations of human bladder tumors, an isochromosome 5p is a consistent marker of the newly established line. The BT-1 cells produce transforming growth factors but do not respond to exogeneous EGF.
Collapse
|
63
|
Schindler D, Seyschab H, Poot M, Hoehn H, Schinzel A, Fryns JP, Tommerup N, Rabinovitch PS. Screening test for ataxia telangiectasia. Lancet 1987; 2:1398-9. [PMID: 2890980 DOI: 10.1016/s0140-6736(87)91288-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
|
64
|
Hoehn H, Koch H, Köhler J, Bettecken T, Kubbies M, Heckl W, Salk D, Rabinovitch PS. Interphase cell flow cytometry as a means of monitoring genomic size in normal and neoplastoid cell cultures. CANCER GENETICS AND CYTOGENETICS 1987; 24:191-204. [PMID: 3791174 DOI: 10.1016/0165-4608(87)90099-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The DNA specific fluorescence of mass cultures and clones derived from human skin and bladder tumor tissue was assayed by flow cytometry. In order to detect and quantitate small fluorescence intensity changes, cytogenetically defined triploid or diploid human fibroblast strains were cocultivated, harvested, and stained with the cell strain of unknown karyotype. The triploid standard (derived from human abortus tissue) proved chromosomally unstable at high passage level. Fifteen male, female, and 45,X strains displayed target-to-standard cell fluorescence ratios commensurate with their respective chromosome constitutions. Interstrain variation was highest among the 45,X strains, although mosaicism could not be detected by conventional cytogenetics. Interclonal fluorescence variation was two- to ten-fold higher among the tumor-derived clones tested. Chromosome counts and subcloning experiments indicate that this increased fluorescence variation is due to genome size variation. The clonal evolution of genome size differences was observed in subclones of chromosomally divergent parental clones. These observations suggest that well controlled flow cytometry can adequately resolve subtle degrees of genome size variation in cultivated human cells. The technique is especially suited for monitoring genome size changes in cultivated tumor cells.
Collapse
|
65
|
Kubbies M, Hoehn H, Rabinovitch PS. Differences in growth factor sensitivity between primary and transformed murine cell cultures revealed by BrdU/Hoechst flow cytometry. EXPERIMENTAL CELL BIOLOGY 1987; 55:225-36. [PMID: 3327716 DOI: 10.1159/000163421] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Spontaneous cell transformation is a common feature of all murine cell cultures grown in vitro for extended periods of time. During early passages, these cultures show either progressively reduced growth or complete cessation of growth; after such a 'crisis' they display increasing growth rates and unlimited lifespan. Here we use a novel bromodeoxyuridine/Hoechst flow-cytometric technique to examine the growth response of diploid and transformed cells of the murine species Micromys minutus under a variety of growth conditions. After spontaneous transformation, growth factor exposure results in increased G0/G1 cell recruitment and higher growth rates than shown by the nontransformed diploid cell fraction. Despite clonal heterogeneity, this difference is seen at all fetal calf serum (FCS) concentrations, although it is most pronounced with low serum. Epidermal growth factor and insulin are shown to act synergistically and promote growth equal to exposures of transformed cultures to 10% FCS. The observed differences in growth factor response between diploid and aneuploid cells could explain the reported lack of a classical growth crisis in growth factor-supplemented media during the spontaneous in vitro transformation of primary cell cultures.
Collapse
|
66
|
Schindler D, Kubbies M, Hoehn H, Schinzel A, Rabinovitch PS. Confirmation of Fanconi's anemia and detection of a chromosomal aberration (1Q12-32 triplication) via BrdU/Hoechst flow cytometry. THE AMERICAN JOURNAL OF PEDIATRIC HEMATOLOGY/ONCOLOGY 1987; 9:172-7. [PMID: 3592130 DOI: 10.1097/00043426-198722000-00014] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Peripheral blood lymphocyte cultures of a patient with clinical evidence of Fanconi's anemia (FA) were investigated by means of BrdU/Hoechst flow cytometry. This technique can be used to differentiate cycling from noncycling cells after PHA stimulation; it also permits the quantitative assessment of cell cycle progression and cell-cycle arrest. A characteristic cell kinetic pattern of combined G2 phase prolongation and G2 phase arrest was observed in the present patient, confirming the clinical diagnosis of FA. An additional finding was the presence of a small subpopulation of peripheral blood cells, refractory to PHA stimulation, and displaying a DNA content 5% greater than that of the diploid cells. BrdU/Hoechst flow cytometry was crucial to the unequivocal demonstration of this subpopulation, which would not have been detected without enrichment by sequential depletion of PHA-responsive cells from the G0/G1 compartment during a 96-h stimulation experiment. The parallel finding of a presumptive triplication affecting the q12-32 segment of chromosome 1 in rare spontaneous divisions of a 40-h peripheral blood culture is consistent with the flow-cytometric detection of elevated DNA content if, as is common in FA, the abnormal cell lineage represents a preleukemic clone of monocytic origin.
Collapse
|
67
|
Kubbies M, Friedl R, Bettecken T, Hoehn H. The fate of the primary diploid population during spontaneous transformation of growth factor-supplemented murine cell cultures. CYTOMETRY 1986; 7:551-7. [PMID: 3536360 DOI: 10.1002/cyto.990070609] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Primary cultures derived from lung and renal tissue of the newborn harvest mouse (Micromys minutus) were serially passaged in media supplemented with epidermal growth factor, hydrocortisone, transferrin, insulin, and triiodothyronine. Although these growth factor supplements eliminated the growth crisis commonly encountered during the initial stages of murine primary cultures, the original diploid cell fraction clearly underwent such a "crisis"; the truly diploid cells invariably disappeared as these cultures reached 20 to 40 population doublings. They were replaced, either gradually or precipitously, by various heteroploid cell fractions. In three of four independent cultures, these "established" cells were hypotetraploid and appeared to be derived from a small number of progenitors already present during the very early (precrisis) culture stages. In contrast to rather frequent DNA changes displayed by clones and subclones derived from the various heteroploid cell lineages, the predominant components of the established mass cultures displayed a highly constant DNA fluorescence pattern. Our results suggest that primary murine cell cultures develop heteroploid cell lineages even if the initial growth crisis is mitigated by growth factor supplements. These heteroploid cells appear to respond more efficiently to stimulation by various growth factors than the primary diploid cell population.
Collapse
|
68
|
Kubbies M, Schindler D, Hoehn H, Rabinovitch PS. BrdU-Hoechst flow cytometry reveals regulation of human lymphocyte growth by donor-age-related growth fraction and transition rate. J Cell Physiol 1985; 125:229-34. [PMID: 4055906 DOI: 10.1002/jcp.1041250209] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
An improved BrdU-Hoechst flow assay was applied to cell kinetic studies of human lymphocyte cultures during a 24-96 hr interval after PHA stimulation. The assay shows that the duration of the initial lag phase and the proportions of noncycling cells increase as a function of donor age, whereas the rates of transition from each cell cycle compartment to the next decrease. Cell cycle arrest occurs in the first S and G2 phase after stimulation of lymphocytes from a 75-year-old donor but not from younger donors. The data are consistent with several models of cell cycle kinetics, so long as these models are modified to include a fraction of noncycling cells in each cell cycle compartment.
Collapse
|
69
|
|
70
|
Kubbies M, Schindler D, Hoehn H, Schinzel A, Rabinovitch PS. Endogenous blockage and delay of the chromosome cycle despite normal recruitment and growth phase explain poor proliferation and frequent edomitosis in Fanconi anemia cells. Am J Hum Genet 1985; 37:1022-30. [PMID: 4050789 PMCID: PMC1684700] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
BrdU-Hoechst flow cytometry was employed to study the proliferation kinetics of blood lymphocytes from patients with Fanconi anemia (FA). Compared to controls, untreated FA lymphocytes show normal response to PHA stimulation, normal G0/G1 exit rates, and normal first S-phase durations. The G2 phase of the first cell cycle, however, is severely prolonged, and 24% of the recruited population become arrested during the first chromosome cycle (S, G2/M phases). The delay suffered during G2 appears to be compensated in part by a subsequent G1 phase duration that is unusually short for postnatal human cells (3.7 +/- 0.5 hrs). In analogy to what has been observed in other cell systems after experimental delays of the chromosome cycle, we therefore postulate that at least some FA cells enter their second growth phase without prior completion of the delayed chromosome cycle. Renewed replication would ensue in such cells without prior passing through mitosis and cytokinesis, leading to endoreduplication, which is a frequent finding in the FA syndrome.
Collapse
|
71
|
Kubbies M, Schindler D, Hoehn H, Rabinovitch PS. Cell cycle kinetics by BrdU-Hoechst flow cytometry: an alternative to the differential metaphase labelling technique. CELL AND TISSUE KINETICS 1985; 18:551-62. [PMID: 2411405 DOI: 10.1111/j.1365-2184.1985.tb00696.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Human lymphocyte cell cycle kinetics was studied in parallel in whole blood and in isolated lymphocyte cultures by differential metaphase labelling and by flow cytometry, employing the principle of quenching of Hoechst fluorescence by BrdU substituted DNA. The BrdU-Hoechst flow technique yields information on the kinetics of cell recruitment and cell cycle progression superior to the differential metaphase staining, since it provides data from interphase cells, including cycle compartment durations, non-cycling cell fractions and transition probabilities. The Smith and Martin model, modified to include a fraction of non-cycling cells, yields excellent correspondence to the experimental data. We show that lymphocytes isolated from Ficoll gradients respond to PHA stimulation with a 4-6 hr delay compared to whole blood cultures or to cultures with autologous serum supplementation. A detailed study of the effects of such culture supplements on lag phase duration, cell cycle compartment length, non-cycling cell fractions and transition probabilities illustrates the application and reproducibility of the flow assay. The potential of the method is further documented with two examples showing the dependence of lymphocyte proliferation on donor age and donor genotype.
Collapse
|
72
|
|
73
|
Salk D, Bryant E, Hoehn H, Johnston P, Martin GM. Growth characteristics of Werner syndrome cells in vitro. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1985; 190:305-11. [PMID: 4083155 DOI: 10.1007/978-1-4684-7853-2_14] [Citation(s) in RCA: 55] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
|
74
|
Salk D, Au K, Hoehn H, Martin GM. Cytogenetic aspects of Werner syndrome. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1985; 190:541-6. [PMID: 4083162 DOI: 10.1007/978-1-4684-7853-2_27] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
|
75
|
Hoehn H, Salk D. Clonal analysis of stable chromosome rearrangements in Bloom's syndrome fibroblasts. CANCER GENETICS AND CYTOGENETICS 1984; 11:405-15. [PMID: 6704941 DOI: 10.1016/0165-4608(84)90021-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
In situ cytogenetic analysis was performed on colonies derived from single cells of cultured skin fibroblast-like strains from two patients with Bloom's syndrome (GM 1492 and GM 2520). Metaphases in all of the colonies displayed structural chromosome rearrangements. Among 212 metaphases from 24 colonies of GM 1492, only 16% were pseudodiploid, and there was a high incidence of de novo rearrangements within individual colonies. There were two "families" of 16 and five colonies, respectively, each containing identical or related aneusomies, and these could be arranged into pedigrees showing clonal evolution. The heterochromatic region of chromosome #1 and the telomeric regions of chromosome arms 2q, 3q, 4p, and 11q were most frequently involved in the rearrangements. In contrast, strain GM 2520 showed less intraclonal variation, was primarily pseudodiploid, and displayed only three clonal types, one of which had extensive subclonal variation (19 of 24 clones). A remarkable finding in GM 2520 was that, in some clones, extra copies of specific chromosome segments were present as translocations. These results caution against the use of strain GM 1492 as a prototype Bloom's syndrome strain for cell biological studies.
Collapse
|