Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1994-4-12
pubmed:abstractText
The relationship between topoisomerase II activity and ribosomal RNA synthesis was investigated using the antitumoral drug VM26, a specific inhibitor of topoisomerase II. For this purpose TG cells, a human tumor cell line, were cultured in the presence of 2.5 microM VM26 for 1 and 3 h; VM26 reduced the topoisomerase II activity, measured in whole cell extracts. In the presence of VM26 the [3H]uridine incorporation into ribosomal RNA was decreased; electron microscopy investigation of nucleoli showed a segregation of nucleolar components. Because VM26 stabilizes the cleavable complex and inhibits the resealing reaction, thus causing potential cleavage sites, we have analyzed the double-strand breaks caused by the drug treatment in the tandem repeat ribosomal DNA (rDNA) genes, by indirect labeling with two probes recognizing the 5' portion of ETS (BES) and the 3' portion of 28S (LS6BE) transcribed gene. In VM26-treated cells rDNA is fragmented and a topoisomerase II preferential cleavage site is present, localized at 1.85 kb in 28S region from 3' EcoRI site.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0014-4827
pubmed:author
pubmed:issnType
Print
pubmed:volume
211
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
36-41
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed:year
1994
pubmed:articleTitle
Inhibition of topoisomerase II activity and its effect on nucleolar structure and function.
pubmed:affiliation
Dipartimento di Patologia Sperimentale, Università degli Studi di Bologna, Italy.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't