Linked Life Data

9484953

Source:http://linkedlifedata.com/resource/pubmed/id/9484953

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1998-3-24
pubmed:abstractText
A number of vinca alkaloids, including vincristine, vinblastine, and vinorelbine, are currently used in cancer chemotherapy. These three vinca alkaloids interact differently with a range of solid and hematologic tumors. To test the possibility that the tubulin isotype composition is an important determinant in antineoplastic efficacy, we determined thermodynamic parameters for vinca alkaloid interactions with purified beta-tubulin isotypes, alphabetaII or alphabetaIII, as well as mixtures of alphabetaII and alphabetaIII, alphabetaII and alphabetaI&IV, or alphabetaIII and alphabetaI&IV (referred to as isotype-depleted tubulin) by quantitative sedimentation velocity. Vincristine-, vinblastine-, or vinorelbine-induced isotype self-association was studied at 25 degrees C in 10 mM Pipes, pH 6.9, 1 mM MgSO4, and 2 mM EGTA in the presence of 50 microM GTP or GDP. For all three drugs, we observed no significant differences in overall affinities, K1K2, or in GDP enhancement of purified isotypes compared to unfractionated tubulin, suggesting that differential antitumor efficacy observed clinically for these vinca alkaloids is not determined by tissue isotype composition. Small, but significant differences in the individual binding parameters, K1 and K2, are found in the vincristine data. In the presence of vincristine and GTP, K1, the affinity of drug for tubulin heterodimers, tends to be larger for purified alphabetaII- or alphabetaIII-tubulin compared to unfractionated tubulin. Furthermore, the apparent dimerization constant, K2app, at physiologically significant drug concentrations is larger for these purified isotypes. When alphabetaII- and alphabetaIII-tubulin are combined, the cooperativity between drug binding and spiral formation approaches that of unfractionated PC-tubulin. These differences are not observed in the presence of vinblastine or vinorelbine. The differences found with vincristine may be implicated in the dose-limiting neurotoxicity found with this drug, but not found with vinblastine or vinorelbine.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0886-1544
pubmed:author
pubmed:issnType
Print
pubmed:volume
39
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
107-21
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
Energetics of vinca alkaloid interactions with tubulin isotypes: implications for drug efficacy and toxicity.
pubmed:affiliation
School of Nursing, University of Mississippi Medical Center, Jackson 39216, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.