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dc.contributor.authorBaghdjian, R B
dc.contributor.authorItzhaki, S
dc.contributor.authorOckey, Charles H
dc.contributor.authorItzhaki, Ruth F
dc.date.accessioned2011-06-16T22:00:45Z
dc.date.available2011-06-16T22:00:45Z
dc.date.issued1982-12-10
dc.identifier.citationStudies on ehrlich ascites tumour cells: DNA synthesis, and template activity of chromatin for DNA polymerase. 1982, 49 (3):169-75 Mol. Cell. Biochem.en
dc.identifier.issn0300-8177
dc.identifier.pmid7162507
dc.identifier.urihttp://hdl.handle.net/10541/133542
dc.description.abstractChromatin obtained from Ehrlich ascites cells on different days after cell inoculation has been assayed for its template activity with added DNA polymerase I. We have found that the template activity is 2 times higher in 7-8 day cell chromatin than in 4-day chromatin. Studies with added polylysine indicate that this increase reflects an increase in initiation sites rather than in accessibility to the enzyme. We have measured the growth fraction, mitotic index and rate of DNA chain growth in the intact cells. The results show that there is a large decrease in growth fraction with age of tumour, the number of cells dropping out of cycle approximately doubling over the period studied. The overall rate of chain growth decreases in the later stages of growth but in a small proportion of cells there is an increase in rate with fewer replicons involved in DNA synthesis. We suggest that in the ascites cells there is a decrease in level of repair and replicative enzymes with age of tumour; this would account both for the increase in initiation sites in the chromatin DNA, for the decrease in number of cells in cycle and for the overall decreased rate of chain growth.
dc.language.isoenen
dc.subject.meshAnimals
dc.subject.meshCarcinoma, Ehrlich Tumor
dc.subject.meshCell Nucleus
dc.subject.meshChromatin
dc.subject.meshDNA Polymerase I
dc.subject.meshDNA Replication
dc.subject.meshDNA, Neoplasm
dc.subject.meshDNA-Directed DNA Polymerase
dc.subject.meshMale
dc.subject.meshMice
dc.subject.meshMitosis
dc.subject.meshPolylysine
dc.subject.meshRNA, Neoplasm
dc.subject.meshTemplates, Genetic
dc.titleStudies on ehrlich ascites tumour cells: DNA synthesis, and template activity of chromatin for DNA polymerase.en
dc.typeArticleen
dc.contributor.departmentPaterson Laboratories, Christie Hospital and Holt Radium Institute, Manchester M20 9BX, UKen
dc.identifier.journalMolecular and Cellular Biochemistryen
html.description.abstractChromatin obtained from Ehrlich ascites cells on different days after cell inoculation has been assayed for its template activity with added DNA polymerase I. We have found that the template activity is 2 times higher in 7-8 day cell chromatin than in 4-day chromatin. Studies with added polylysine indicate that this increase reflects an increase in initiation sites rather than in accessibility to the enzyme. We have measured the growth fraction, mitotic index and rate of DNA chain growth in the intact cells. The results show that there is a large decrease in growth fraction with age of tumour, the number of cells dropping out of cycle approximately doubling over the period studied. The overall rate of chain growth decreases in the later stages of growth but in a small proportion of cells there is an increase in rate with fewer replicons involved in DNA synthesis. We suggest that in the ascites cells there is a decrease in level of repair and replicative enzymes with age of tumour; this would account both for the increase in initiation sites in the chromatin DNA, for the decrease in number of cells in cycle and for the overall decreased rate of chain growth.


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