Linked Life Data

1995027

Source:http://linkedlifedata.com/resource/pubmed/id/1995027

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1991-3-22
pubmed:abstractText
Murine leukemia L1210 cells selected for progressive resistance to doxorubicin (DOX) display both the multidrug resistant (MDR) phenotype and reductions in drug induced topoisomerase II-mediated DNA cleavage in nuclear extracts (Ganapathi, R.; Grabowski, D.; Ford, J.; Heiss, C.; Kerrigan, D.; Pommier, Y., Cancer Commun. 1:217-224; 1989). The present study was performed to characterize the results of exposure of the sensitive (S) and progressively DOX-resistant (10-fold, R1, and 40-fold, R2) L1210 cells to the topoisomerase II inhibitor, etoposide, and to investigate the modulating effects of the calmodulin inhibitor, trifluoperazine (TFP). Immunoblotting experiments indicated no apparent decrease in the p170 or p180 isoforms of topoisomerase II in the resistant sublines versus parental sensitive cells. Cross-resistance to etoposide (VP-16) was similar to that of DOX (10- and 40-fold). A non-cytotoxic concentration of 5 microM TFP enhanced cell kill 1.5- fold in the sensitive and 3- to 5-fold in the progressively DOX-resistant cells. Accumulation of VP-16 was 30% to 50% lower in the resistant sublines versus similarly treated sensitive cells, and a marked enhancement of drug uptake in the presence of TFP was observed in the sensitive but not in the resistant cells exposed to equivalent extracellular levels of VP-16. Although equimolar concentrations of VP-16 produced fewer DNA single strand breaks (SSB) and DNA protein crosslinks (DPC) in the resistant versus sensitive cells, similar DNA damage was apparent when S and R1, but not R2, cells were treated at VP-16 concentrations that produced equivalent cell death.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0955-3541
pubmed:author
pubmed:issnType
Print
pubmed:volume
3
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
37-44
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1991
pubmed:articleTitle
Trifluoperazine modulation of resistance to the topoisomerase II inhibitor etoposide in doxorubicin resistant L1210 murine leukemia cells.
pubmed:affiliation
Research Institute, Cleveland Clinic Foundation, Ohio 44195.
pubmed:publicationType
Journal Article, In Vitro, Research Support, U.S. Gov't, P.H.S.