Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
7
pubmed:dateCreated
1996-10-9
pubmed:abstractText
The in vitro cytotoxicity of the combination of azidothymidine (AZT) and 5-fluorouracil (5-FU) against the human colorectal cancer cells SW-480, SW-620 and COLO-320DM was evaluated. The cytotoxic effects of 5-FU and AZT were determined by the assay using 2,3-bis(2-methoxy-4-nitro-5-sulfophenil)-2H-tetrazolium-5-carbo xanilide inner salt (XXT), while drug-induced DNA strand-breaks were measured using a fluorometric analysis of DNA unwinding. After an exposure of 72 h, 5-FU and AZT induced a dose-dependent cytotoxicity against each cell line. The addition of 3, 10 and 30 microM AZT to various concentrations of 5-FU, as well as the addition of 0.5, 1 and 3 microns 5-FU to various concentrations of AZT, resulted in an enhanced cytotoxic effect. Isobologram analysis and the combination index (CI) method demonstrated that the interaction between 5-FU and AZT was clearly synergistic in each cell line, except for the 30% level of effect in SW-620, where borderline synergism was observed. The evaluation of DNA strand-breaks after an exposure of 16 h to 5-FU, AZT or 5-FU + AZT demonstrated that the 5-FU + AZT combination produced the greatest DNA damage, and that this interaction was synergistic in each cell line. In conclusion, our study supports the evidence that the potential antitumour activity of AZT can be modulated by combining it with agents which inhibit thymidylate (dTMP) formation, such as 5-FU, and that the increased cytotoxicity is related to enhanced DNA damage. These findings should encourage further experimental and clinical studies of the potential use of AZT in combination with inhibitors of de novo dTMP synthesis.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0959-8049
pubmed:author
pubmed:issnType
Print
pubmed:volume
32A
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1219-26
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1996
pubmed:articleTitle
Azidothymidine in combination with 5-fluorouracil in human colorectal cell lines: in vitro synergistic cytotoxicity and DNA-induced strand-breaks.
pubmed:affiliation
Dipartimento di Biomedicina, Università di Pisa, Italy.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't