Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1998-8-6
pubmed:abstractText
We have shown that both DNA topoisomerase (topo) IIalpha and beta are in vivo targets for etoposide using a new assay which directly measures topo IIalpha and beta cleavable complexes in individual cells after treatment with topo II targeting drugs. CCRF-CEM human leukemic cells were exposed to etoposide for 2 hr, then embedded in agarose on microscope slides before cell lysis. DNA from each cell remained trapped in the agarose and covalently bound topo II molecules from drug-stabilized cleavable complexes remained associated with the DNA. The covalently bound topo II was detected in situ by immunofluorescence. Isoform-specific covalent complexes were detected with antisera specific for either the alpha or beta isoform of topo II followed by a fluorescein isothiocyanate-conjugated second antibody. DNA was detected using the fluorescent stain Hoechst 33258. A cooled slow scan charged coupled device camera was used to capture images. A dose-dependent increase in green immunofluorescence was observed when using antisera to either the alpha or beta isoforms of topo II, indicating that both isoforms are targets for etoposide. We have called this the TARDIS method, for trapped in agarose DNA immunostaining. Two key advantages of the TARDIS method are that it is isoform-specific and that it requires small numbers of cells, making it suitable for analysis of samples from patients being treated with topo II-targeting drugs. The isoform specificity will enable us to extend our understanding of the mechanism of interaction between topo II-targeting agents and their target, the two human isoforms.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0026-895X
pubmed:author
pubmed:issnType
Print
pubmed:volume
54
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
78-85
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
Etoposide targets topoisomerase IIalpha and IIbeta in leukemic cells: isoform-specific cleavable complexes visualized and quantified in situ by a novel immunofluorescence technique.
pubmed:affiliation
Department of Biochemistry and Genetics, The Medical School, The University of Newcastle-upon-Tyne, Newcastle-upon-Tyne NE2 4HH, United Kingdom.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't