Linked Life Data

1706219

Source:http://linkedlifedata.com/resource/pubmed/id/1706219

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
7
pubmed:dateCreated
1991-4-23
pubmed:abstractText
The effects of fludarabine triphosphate (Fara-ATP), 1-beta-D-arabinofuranosylcytosine 5'-triphosphate (ara-CTP), and aphidicolin on primer RNA and DNA synthesis in human CCRF-CEM leukemia cells were investigated. RNA-primed Okazaki fragment synthesis was monitored by first incubating whole cell lysates for 10 min in the presence or absence of the compound and then following the incorporation of [alpha-32P]ATP and [3H]dTTP into the primer RNA and DNA portions, respectively, of the Okazaki fragments. In whole cell lysates the degree of DNA synthesis inhibition induced by Fara-ATP was directly related to the extent of primer RNA synthesis inhibition over the entire range of Fara-ATP concentrations tested (10-50 microM). In contrast, primer RNA formation was stimulated by concentrations of ara-CTP (25-200 microM) and aphidicolin (0.5-5 micrograms/ml) that inhibited DNA synthesis. The primer RNA recovered from cell lysates incubated with either Fara-ATP, ara-CTP, or aphidicolin was of normal length, predominately 11 nucleotides. Fara-ATP was a more potent inhibitor of the polydeoxythymidylate primase activity than of the DNA polymerase alpha/delta activities present in the 100,000 x g supernatants of CCRF-CEM cells. Fara-ATP was a noncompetitive inhibitor of DNA primase with respect to ATP [50% inhibitory concentration, 2.3 +/- 0.3 (SD) microM, Ki = 6.1 +/- 0.3 (SE) microM] and the Km(ATP)/Ki (Fara-ATP) was 25. The 50% inhibitory concentration values of Fara-ATP for DNA polymerases alpha/delta activities on calf thymus DNA were 43 +/- 1.6 (SD) microM and greater than 100 microM with respect to dATP and dTTP. The effects of ara-CTP and aphidicolin on these enzymes were opposite those seen with Fara-ATP, since 50% inhibitory concentrations of either ara-CTP or aphidicolin for DNA polymerases alpha/delta did not inhibit polydeoxythymidylate primase activity. The results provide evidence that fludarabine phosphate blocks DNA synthesis in CCRF-CEM cells through inhibition of primer RNA formation. In contrast, the accumulation of primer RNA and RNA-primed Okazaki fragments that is induced by ara-CTP and aphidicolin could lead to the rereplication and amplification of chromosomal DNA segments.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/Aphidicolin, http://linkedlifedata.com/resource/pubmed/chemical/Arabinofuranosylcytosine..., http://linkedlifedata.com/resource/pubmed/chemical/DNA, Neoplasm, http://linkedlifedata.com/resource/pubmed/chemical/DNA Primase, http://linkedlifedata.com/resource/pubmed/chemical/DNA-Directed DNA Polymerase, http://linkedlifedata.com/resource/pubmed/chemical/Deoxyguanine Nucleotides, http://linkedlifedata.com/resource/pubmed/chemical/Diterpenes, http://linkedlifedata.com/resource/pubmed/chemical/N(2)-(4-n-butylphenyl)-2'-deoxyguano..., http://linkedlifedata.com/resource/pubmed/chemical/RNA, http://linkedlifedata.com/resource/pubmed/chemical/RNA Nucleotidyltransferases, http://linkedlifedata.com/resource/pubmed/chemical/RNA primers, http://linkedlifedata.com/resource/pubmed/chemical/Vidarabine Phosphate, http://linkedlifedata.com/resource/pubmed/chemical/ara-ATP, http://linkedlifedata.com/resource/pubmed/chemical/fludarabine monophosphate
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0008-5472
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
51
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1829-35
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1991
pubmed:articleTitle
Inhibition of primer RNA formation in CCRF-CEM leukemia cells by fludarabine triphosphate.
pubmed:affiliation
Department of Biochemistry, Bowman Gray School of Medicine, Wake Forest University, Winston-Salem, North Carolina 27103.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't