Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1995-3-2
pubmed:abstractText
The proliferation of normal non-tumourigenic mouse fibroblasts is stringently controlled by regulatory mechanisms located in the postmitotic stage of G1 (which we have designated G1pm). Upon exposure to growth factor depletion or a lowered de novo protein synthesis, the normal cells leave the cell cycle from G1pm and enter G0. The G1 pm phase is characterized by a remarkably constant length (the duration of which is 3 h in Swiss 3T3 cells), whereas the intercellular variability of intermitotic time is mainly ascribable to late G1 or pre S phase (G1ps) (Zetterberg & Larsson (1985) Proc. Natl. Acad. Sci. USA 82, 5365). As shown in the present study two tumour-transformed derivatives of mouse fibroblasts, i.e. BPA31 and SVA31, did not respond at all, or only responded partially, respectively, to serum depletion and inhibition of protein synthesis. If the tumour cells instead were subjected to 25-hydroxycholesterol (an inhibitor of 3-hydroxy-3 methyglutaryl coenzyme A reductase activity), their growth was blocked as measured by growth curves and [3H]-thymidine uptake. Time-lapse analysis revealed that the cells were blocked specifically in early G1 (3-4 h after mitosis), and DNA cytometry confirmed that the arrested cells contained a G1 amount of DNA. Closer kinetic analysis revealed that the duration of the postmitotic phase containing cells responsive to 25-hydroxycholesterol was constant. These data suggest that transformed 3T3 cells also contain a 'G1pm program', which has to be completed before commitment to mitosis. By repeating the experiments on a large number of tumour-transformed cells, including human carcinoma cells and glioma cells, it was demonstrated that all of them possessed a G1pm-like stage. Our conclusion is that G1pm is a general phenomenon in mammalian cells, independent of whether the cells are normal or neoplastic.
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
28
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
33-43
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:7833384-3T3 Cells, pubmed-meshheading:7833384-Animals, pubmed-meshheading:7833384-Breast Neoplasms, pubmed-meshheading:7833384-Cell Cycle, pubmed-meshheading:7833384-Cell Division, pubmed-meshheading:7833384-Cell Line, Transformed, pubmed-meshheading:7833384-Cell Transformation, Neoplastic, pubmed-meshheading:7833384-Cycloheximide, pubmed-meshheading:7833384-DNA, Neoplasm, pubmed-meshheading:7833384-Fibroblasts, pubmed-meshheading:7833384-G1 Phase, pubmed-meshheading:7833384-Glioma, pubmed-meshheading:7833384-Humans, pubmed-meshheading:7833384-Hydroxycholesterols, pubmed-meshheading:7833384-Hydroxymethylglutaryl-CoA Reductase Inhibitors, pubmed-meshheading:7833384-Mice, pubmed-meshheading:7833384-Mice, Inbred BALB C, pubmed-meshheading:7833384-Mitosis, pubmed-meshheading:7833384-Neoplasms, pubmed-meshheading:7833384-Time Factors, pubmed-meshheading:7833384-Tumor Cells, Cultured
pubmed:year
1995
pubmed:articleTitle
Existence of a commitment program for mitosis in early G1 in tumour cells.
pubmed:affiliation
Department of Tumor Pathology, Karolinska Institute, Karolinska Hospital, Stockholm, Sweden.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't