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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1993-3-31
pubmed:abstractText
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.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0960-7722
pubmed:author
pubmed:issnType
Print
pubmed:volume
26
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
45-54
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1993
pubmed:articleTitle
Induction of replicative senescence by 5-azacytidine: fundamental cell kinetic differences between human diploid fibroblasts and NIH-3T3 cells.
pubmed:affiliation
Department of Human Genetics, University of Würzburg, Germany.
pubmed:publicationType
Journal Article, Comparative Study