Effects of prolonged quiescence on nuclei and chromatin of WI‐38 fibroblasts

Rossini, Mara; Lin, Jung‐Chung; Baserga, Renato

doi:10.1002/jcp.1040880102

Cited by 53 publications

(24 citation statements)

References 51 publications

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“…The enhancement of growth inhibitory activity in our assay by a deep Go state of quiescence appears to parallel the results obtained in heterokaryon experiments (1,6,26,30,39), suggesting that growth inhibition may be mediated by similar mechanisms in both assays. On the other hand, it has been reported that HeLa cells exhibit a dominant phenotype in heterokaryon fusions, i.e., induce DNA replication in nuclei from quiescent or senescent cells (19,23,26,39).…”

Section: Discussionsupporting

confidence: 84%

“…Genomic DNAs were prepared from quiescent cultures of W138 human embryo fibroblasts in which quiescence had been induced either by density arrest in medium containing 10% fetal calf serum or by serum deprivation in medium containing 0.5% fetal calf serum. The latter (low-serum) condition has previously been shown to induce a characteristic deep Go state of quiescence that mediates growth inhibition in heterokaryon experiments (1,6,26,30,39). These DNAs were mixed with the marker plasmid pRSVneo (10) and transfected into HeLa S3 cells growing in monolayer culture.…”

Section: Resultsmentioning

confidence: 99%

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Specific growth inhibitory sequences in genomic DNA from quiescent human embryo fibroblasts.

Padmanabhan¹,

Howard²,

Howard³

1987

Mol. Cell. Biol.

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We used HeLa cells as recipients in a gene transfer assay to characterize DNA sequences that negatively regulate mammalian cell growth. In this assay, genomic DNA from quiescent human embryo fibroblasts was more inhibitory for HeLa replication than was DNA from either Escherichia coli or HeLa cells. Surprisingly, growth inhibitory activity depended on the growth state of the cells from which genomic DNA was prepared; it was strongest in DNA prepared from serum-deprived, quiescent embryo fibroblasts. This latter observation implies a role for DNA modification(s) in regulating the activity of the inhibitory sequences detected in our assay. The level of the observed growth inhibitory activity was sometimes high, suggesting that the relevant sequences may be abundantly represented in the mammalian genome. We speculate that these findings may provide new insights into the molecular mechanisms involved in cellular quiescence and in vitro senescence.Control of mammalian cell growth appears to be mediated by a balance between positive and negative stimuli. Members of the proto-oncogene family have been intensively studied as effectors of positive growth regulation (3). The molecular mechanisms mediating negative regulation of cell proliferation are, in comparison, less clearly defined. Genes have been cloned for several proteins possessing growth inhibitory activity, including transforming growth factor , which is bifunctional with respect to replication (8,29,44), and members of the interferon family (42); it seems likely, however, that there remains to be identified a much larger number of genes coding for growth inhibitory proteins. Important evidence for negative growth regulation has been obtained from studies of heterokaryons formed by fusion of normal replicating cells with either deeply quiescent cells or senescent cells (6,20,23,26,39,40,45). In such experiments, entry into the S phase of the cell cycle can be strongly inhibited by the nonreplicating partner. Additional evidence for negative growth control has been provided by experiments with somatic cell hybrids for which limitation of proliferative potential (5, 24, 25) and suppression of tumorigenicity (2,7,12,15,31,32,(36)(37)(38) have been demonstrated by a number of laboratories. Although the heterokaryon and somatic cell hybrid approaches have provided very important insights, they do not afford a straightforward means of obtaining molecular clones of the relevant genes.We

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Section: Discussionsupporting

confidence: 84%

Section: Resultsmentioning

confidence: 99%

Specific growth inhibitory sequences in genomic DNA from quiescent human embryo fibroblasts.

Padmanabhan¹,

Howard²,

Howard³

1987

Mol. Cell. Biol.

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“…These data are consistent with the idea that cellular ageing is associated with events occurring after the loss of the cells' ability to divide Evans, 1976b). In sup port of this suggestion, it has been reported that changes occurring in RNA transcription and in the kinetic properties of cells held 'quiescent' for long periods were similar to those occurring during the later part of the in vitro life span (Augenlicht and Baserga, 1974;Evans, 1976b;Rossini et al, 1976). Our own preliminary studies with early passage ( p i3/25) He 125 cells held in 'quiescence' for 11 days by repeated medium changing also confirm this observation since a decrease in template activity was noted in these cells compared with repli cate cultures which had just attained 'quies cence' (370 compared with 580cpm/jug DNA).…”

Section: Discussionsupporting

confidence: 79%

Influence of Growth State on Relationship between Nuclear Template Activity and in vitro ‘Ageing’

Whatley¹,

Hill²

1980

Gerontology

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A reduction in nuclear template activity occurred in He 125 cell cultures only after the expression of a reduction in growth ability. This suggests that these alterations in template activity are terminal events occurring late in the culture life span. Both the rate of loss of template activity and its qualitative aspects were influenced by the growth state of the cultures compared. Therefore, these factors should be taken into account in the analyses of the relationship between in vitro ‘ageing’ and nuclear template activity.

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“…Resting lymphocytes may be in a deeper Go state and may, upon stimulation i, amino-acid-deficient medium, be partially activated to become arrested in a state equivalent to that of quiescent densitydependent cells. The existence of various depths of GO state has been recently suggested [24].…”

Section: Discussionmentioning

confidence: 99%

Phytohaemagglutinin Stimulation of Human Lymphocytes during Amino-Acid Deprivation. RNA Polymerase I Activity of Isolated Nuclei

Dauphinais¹,

Waithe²

1977

Eur J Biochem

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Endogenous RNA polymerase I activity of nuclei isolated from human lymphocytes stimulated during lysine deprivation was studied. The following results were obtained.1. Lysine deprivation does not inhibit RNA polymerase I in resting lymphocytes nor does it prevent the early two-fold increase in enzyme activity induced by phytohaemagglutinin. It does, however, prevent further increase.2. The early increase in RNA polymerase I activity in phytohaemaggluiinin-stimulated lysinedeprived cultures is stable for at least 24 h, in spite of the severe inhibition of protein synthesis caused by the amino acid deficiency.3. The RNA polymerase I activity in phytohaemagglutinin-stimulated lysine-deprived cultures increases immediately upon replacement of the amino acid at any time during culture.4. Inhibition of protein synthesis by cycloheximide during culture results in rapid decay of RNA polymerase I activity in resting lymphocytes and in lymphocytes stimulated in complete medium. Although it prevents the reversal of inhibition upon replacement of lysine, it reduces only slightly the enzyme activity in phytohaemagglutinin-stimulated lysine-deprived cultures.5. Addition of cycloheximide at the same time as phytohaemagglutinin prevents any increase in RNA polymerase I activity in complete medium or in medium lacking lysine.These results show that lymphocytes stimulated in the absence of lysine do not remain in, nor do they revert to, quiescence (Go phase) and that during the early response to phytohaemagglutinin, a stable component of increased transcriptional activity whose synthesis or function is sensitive to cycloheximide is unaffected by lysine deficiency, thus permitting partial activation in lysine-deprived cultures.

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Effects of prolonged quiescence on nuclei and chromatin of WI‐38 fibroblasts

Cited by 53 publications

References 51 publications

Specific growth inhibitory sequences in genomic DNA from quiescent human embryo fibroblasts.

Specific growth inhibitory sequences in genomic DNA from quiescent human embryo fibroblasts.

Influence of Growth State on Relationship between Nuclear Template Activity and in vitro ‘Ageing’

Phytohaemagglutinin Stimulation of Human Lymphocytes during Amino-Acid Deprivation. RNA Polymerase I Activity of Isolated Nuclei

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