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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
19
pubmed:dateCreated
2011-5-13
pubmed:abstractText
Immunomodulatory derivatives of thalidomide (IMiD compounds), such as pomalidomide and lenalidomide, are highly active in multiple myeloma (MM) treatment. However, the precise mechanisms of action and resistance in MM are unresolved. Here we show that IMiD compounds down-regulate CCAAT/enhancer-binding protein-? (C/EBP?) resulting in abrogation of cell proliferation. Overexpression of C/EBP? rescued MM cells from IMiD-induced inhibition of proliferation, indicating that C/EBP? is critical in mediating antiproliferative effects. IMiD-induced decrease of C/EBP? protein led to impaired transcription of interferon regulatory factor 4 (IRF4). Down-regulation of IRF4 by lenalidomide was confirmed by longitudinal studies of bone marrow samples from 23 patients obtained before and during lenalidomide treatment using CD138?/IRF4? double labeling. In contrast to down-regulation of C/EBP? protein, IMiD compounds did not alter C/EBP? mRNA levels or protein stability, suggesting translational regulation of C/EBP?. We could demonstrate that C/EBP? protein expression is under eIF4E-translational control in MM. Furthermore, inhibition of the eIF4E-C/EBP? axis by IMiD compounds was not observed in IMiD-resistant MM cells. However, targeting translation at a different level by inhibiting eukaryotic translation initiation factor 4E-binding protein 1 phosphorylation overcame resistance, suggesting that this pathway is critical and might be a target to overcome drug resistance.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
1528-0020
pubmed:author
pubmed:issnType
Electronic
pubmed:day
12
pubmed:volume
117
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
5157-65
pubmed:meshHeading
pubmed-meshheading:21389327-Apoptosis, pubmed-meshheading:21389327-Blotting, Western, pubmed-meshheading:21389327-CCAAT-Enhancer-Binding Protein-beta, pubmed-meshheading:21389327-Cell Separation, pubmed-meshheading:21389327-Down-Regulation, pubmed-meshheading:21389327-Eukaryotic Initiation Factor-4E, pubmed-meshheading:21389327-Flow Cytometry, pubmed-meshheading:21389327-Gene Expression Regulation, pubmed-meshheading:21389327-Gene Knockdown Techniques, pubmed-meshheading:21389327-Humans, pubmed-meshheading:21389327-Immunohistochemistry, pubmed-meshheading:21389327-Immunologic Factors, pubmed-meshheading:21389327-Interferon Regulatory Factors, pubmed-meshheading:21389327-Multiple Myeloma, pubmed-meshheading:21389327-Protein Biosynthesis, pubmed-meshheading:21389327-Reverse Transcriptase Polymerase Chain Reaction, pubmed-meshheading:21389327-Thalidomide, pubmed-meshheading:21389327-Transfection
pubmed:year
2011
pubmed:articleTitle
IMiD immunomodulatory compounds block C/EBP{beta} translation through eIF4E down-regulation resulting in inhibition of MM.
pubmed:affiliation
Department of Medicine, Division of Hematology/Oncology, University of Pittsburgh Cancer Institute, Pittsburgh, PA, USA.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't