Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
1998-3-24
pubmed:abstractText
Cyclin B1 plays a critical role in regulating cell-cycle progression from G2 through M phase (including exit from M phase). In this study, we investigated the relationship between taxol-induced M-phase arrest, disruption of the cyclin B1-regulation pathway and apoptosis in KB cells. Continuous exposure of KB cells to 0.5 microg/ml taxol caused mitotic arrest and >90% cell death at 48 hr. Mitotic blockade peaked at 24 hr, with 68% of cells in mitosis at that time compared with 3% at baseline, and decreased thereafter. Apoptosis assessed by morphological changes and DNA ladder fragmentation was a later event, peaking at 48 hr (later time points were not studied). Taxol also caused an increase in cyclin B1 accumulation, as assessed by Western blot analysis, and stimulated cyclin B1-dependent kinase. Cyclin B1 accumulation and kinase stimulation peaked at 12 and 24 hr, respectively, at which times they were 5-fold and 90-fold higher than in control untreated cells. These effects decreased thereafter. All taxol-induced cellular effects were abrogated by the protein and RNA synthesis inhibitors cycloheximide and actinomycin D. In contrast, the endonuclease inhibitors aurintricarboxilic acid and zinc markedly inhibited taxol-induced DNA ladder fragmentation without altering taxol-induced cell-cycle arrest, cyclin B1 accumulation, activation of cyclin B1 kinase activity and cytotoxicity. We conclude that taxol-induced stimulation of cyclin B1-dependent kinase activity parallels mitotic arrest, is more pronounced than mitotic arrest and precedes the induction of programmed cell death.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0020-7136
pubmed:author
pubmed:issnType
Print
pubmed:day
16
pubmed:volume
75
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
925-32
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
Accumulation of cyclin B1, activation of cyclin B1-dependent kinase and induction of programmed cell death in human epidermoid carcinoma KB cells treated with taxol.
pubmed:affiliation
Department of Thoracic/Head and Neck Medical Oncology, The University of Texas M.D. Anderson Cancer Center, Houston 77030, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't