Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
13
pubmed:dateCreated
2001-6-29
pubmed:abstractText
Interactions between the checkpoint abrogator UCN-01 and several pharmacological inhibitors of the mitogen-activated protein kinase (MAPK) kinase (MEK)/MAPK pathway have been examined in a variety of human leukemia cell lines. Exposure of U937 monocytic leukemia cells to a marginally toxic concentration of UCN-01 (e.g., 150 nM) for 18 h resulted in phosphorylation/activation of p42/44 MAPK. Coadministration of the MEK inhibitor PD184352 (10 microM) blocked UCN-01-induced MAPK activation and was accompanied by marked mitochondrial damage (e.g., cytochrome c release and loss of DeltaPsi(m)), caspase activation, DNA fragmentation, and apoptosis. Similar interactions were noted in the case of other MEK inhibitors (e.g., PD98059; U0126) as well as in multiple other leukemia cell types (e.g., HL-60, Jurkat, CCRF-CEM, and Raji). Coadministration of PD184352 and UCN-01 resulted in reduced binding of the cdc25C phosphatase to 14-3-3 proteins, enhanced dephosphorylation/activation of p34(cdc2), and diminished phosphorylation of cyclic AMP-responsive element binding protein. The ability of UCN-01, when combined with PD184352, to antagonize cdc25C/14-3-3 protein binding, promote dephosphorylation of p34(cdc2), and potentiate apoptosis was mimicked by the ataxia telangectasia mutation inhibitor caffeine. In contrast, cotreatment of cells with UCN-01 and PD184352 did not substantially increase c-Jun-NH(2)-terminal kinase activation nor did it alter expression of Bcl-2, Bcl-x(L), Bax, or X-inhibitor of apoptosis. However, coexposure of U937 cells to UCN-01 and PD184352 induced a marked increase in p38 MAPK activation. Moreover, SB203580, which inhibits multiple kinases including p38 MAPK, partially antagonized cell death. Lastly, although UCN-01 +/- PD184352 did not induce p21(CIP1), stable expression of a p21(CIP1) antisense construct significantly increased susceptibility to this drug combination. Together, these findings indicate that exposure of leukemic cells to UCN-01 leads to activation of the MAPK cascade and that interruption of this process by MEK inhibition triggers perturbations in several signaling and cell cycle regulatory pathways that culminate in mitochondrial injury, caspase activation, and apoptosis. They also raise the possibility that disrupting multiple signaling pathways, e.g., by combining UCN-01 with MEK inhibitors, may represent a novel antileukemic strategy.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/2-(2-chloro-4-iodophenylamino)-N-cyc..., http://linkedlifedata.com/resource/pubmed/chemical/7-hydroxystaurosporine, http://linkedlifedata.com/resource/pubmed/chemical/Alkaloids, http://linkedlifedata.com/resource/pubmed/chemical/Benzamides, http://linkedlifedata.com/resource/pubmed/chemical/Butadienes, http://linkedlifedata.com/resource/pubmed/chemical/Caspases, http://linkedlifedata.com/resource/pubmed/chemical/Enzyme Inhibitors, http://linkedlifedata.com/resource/pubmed/chemical/Flavonoids, http://linkedlifedata.com/resource/pubmed/chemical/Mitogen-Activated Protein Kinase..., http://linkedlifedata.com/resource/pubmed/chemical/Nitriles, http://linkedlifedata.com/resource/pubmed/chemical/PD 98059, http://linkedlifedata.com/resource/pubmed/chemical/Staurosporine, http://linkedlifedata.com/resource/pubmed/chemical/U 0126
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0008-5472
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
61
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
5106-15
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed-meshheading:11431348-Alkaloids, pubmed-meshheading:11431348-Antineoplastic Combined Chemotherapy Protocols, pubmed-meshheading:11431348-Apoptosis, pubmed-meshheading:11431348-Benzamides, pubmed-meshheading:11431348-Butadienes, pubmed-meshheading:11431348-Caspases, pubmed-meshheading:11431348-Drug Synergism, pubmed-meshheading:11431348-Enzyme Activation, pubmed-meshheading:11431348-Enzyme Inhibitors, pubmed-meshheading:11431348-Flavonoids, pubmed-meshheading:11431348-HL-60 Cells, pubmed-meshheading:11431348-Humans, pubmed-meshheading:11431348-Jurkat Cells, pubmed-meshheading:11431348-Leukemia, pubmed-meshheading:11431348-MAP Kinase Signaling System, pubmed-meshheading:11431348-Mitochondria, pubmed-meshheading:11431348-Mitogen-Activated Protein Kinase Kinases, pubmed-meshheading:11431348-Nitriles, pubmed-meshheading:11431348-Staurosporine, pubmed-meshheading:11431348-Tumor Cells, Cultured, pubmed-meshheading:11431348-U937 Cells
pubmed:year
2001
pubmed:articleTitle
Pharmacological inhibitors of the mitogen-activated protein kinase (MAPK) kinase/MAPK cascade interact synergistically with UCN-01 to induce mitochondrial dysfunction and apoptosis in human leukemia cells.
pubmed:affiliation
Division of Hematology/Oncology, Medical College of Virginia, Richmond, Virginia 23298, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't