Linked Life Data

12118331

Source:http://linkedlifedata.com/resource/pubmed/id/12118331

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2002-7-15
pubmed:abstractText
A clinically relevant dose (2.0 Gy) of ionizing radiation (IR) was employed to determine if subsequent exposure to the protein kinase C (PKC) and Chk 1 inhibitor UCN-01 for 24 h could abrogate IR-induced G2/M arrest and promote apoptosis in U937 leukemic cells ectopically expressing Bcl-2 (U937/Bcl-2). To this end, empty-vector control (U937/pCEP4) and U937/Bcl-2 cells were exposed to two UCN-01 concentrations following IR: i) a 50 nM concentration, which by itself was minimally toxic to both cell lines, and ii) a 150 nM concentration, which modestly induced apoptosis (e.g., ~19%) in control cells after 24 h. The effects of UCN-01 on IR responses were examined in relation to apoptosis induction, suspension culture growth inhibition, loss of clonogenic survival, and cell cycle perturbations. IR (2 Gy) alone minimally induced apoptosis in both U937 transfectant cell lines (e.g., <5% at 24 h in each case). Although UCN-01 failed to potentiate IR-mediated apoptosis at either early (e.g., 24 h) or late (e.g., 72 h) intervals, exposure to 50 or 150 nM UCN-01 resulted in a significant, albeit modest, reduction in proliferation and colony formation in irradiated U937/pCEP4 and U937/Bcl-2 cells. Despite failing to enhance apoptosis, UCN-01 treatment abrogated IR-induced G2/M arrest in both cell lines, an event associated with enhanced activation of cyclin-dependent kinase 1 (cdk1), promotion of G0/G1 arrest, and dephosphorylation of the retinoblastoma protein (pRb). Together, these findings indicate that exposure of U937 cells ectopically-expressing Bcl-2 to the combination of UCN-01 + IR leads to a further reduction in cell proliferation, and that this phenomenon appears to involve a non-apoptotic mechanism.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
1019-6439
pubmed:author
pubmed:issnType
Print
pubmed:volume
21
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
351-9
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
2002
pubmed:articleTitle
7-hydroxystaurosporine (UCN-01) and ionizing radiation combine to inhibit the growth of Bcl-2-overexpressing U937 leukemia cells through a non-apoptotic mechanism.
pubmed:affiliation
Department of Medicine, Virginia Commonwealth University, Medical College of Virginia, Richmond, VA 23298, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.