Linked Life Data

17384279

Source:http://linkedlifedata.com/resource/pubmed/id/17384279

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:dateCreated
2007-3-26
pubmed:abstractText
The chimeric bcr-abl gene encodes a constitutively active tyrosine kinase that leads to abnormal transduction of growth and survival signals leading to chronic myeloid leukemia (CML). According to our previous observations, in vitro differentiation of several erythroid cell lines is accompanied by the downregulation of extracellular signal-regulated kinases (ERK)1/2 mitogen-activated protein kinase (MAPK) activities. In this work we investigated whether ERKs have a decisive role in either the erythroid differentiation process or apoptosis of bcr-abl+ K562 cells by means of direct (MEK1/2 inhibitor UO126) and indirect (reduced Bcr-Abl function) inhibition of their activities. We found that both Gleevec and UO126 induced hemoglobin expression. Gleevec treatment reduced the phosphorylation of Bcr-Abl, ERK and STAT-5 for up to 24 h, decreased Bcl-XL levels, and induced caspase-3-dependent apoptosis. In contrast, UO126 treatment resulted in only a transient decrease of ERK activity and did not induce cell death. For studying the effect of reduced Bcr-Abl function on erythroid differentiation at the level of the bcr-abl transcript, we applied the siRNA approach. Stable degradation of bcr-abl mRNA was achieved by using a retroviral vector with enhanced green fluorescent protein (EGFP) reporter. Despite a high (>90%) transduction efficiency we detected only a transient decrease in Bcr-Abl protein and in phosphorylated ERK1/2 levels. This transient change in Bcr-Abl signaling was sufficient to induce hemoglobin expression without significant cell death. These results suggest that by transiently reducing Bcr-Abl function it is possible to overcome the differentiation blockade without evoking apoptosis in CML cells and that reduced ERK activity may have a crucial role in this process.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0077-8923
pubmed:author
pubmed:issnType
Print
pubmed:volume
1090
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
344-54
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:year
2006
pubmed:articleTitle
Reduction of Bcr-Abl function leads to erythroid differentiation of K562 cells via downregulation of ERK.
pubmed:affiliation
National Medical Center, Department of Molecular Cell Biology, H-1113 Budapest, Dioszegi 64, Hungary.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't