Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
11
pubmed:dateCreated
2005-3-10
pubmed:abstractText
The FOXO family of Forkhead transcription factors, regulated by the phosphoinositide-3-kinase-Akt pathway, is involved in cell cycle regulation and apoptosis. Strong expression of HER2, a receptor tyrosine kinase oncogene, in cancers has been associated with a poor prognosis. Recently, FOXO4 was shown to regulate the transcription of the cyclin-dependent kinase inhibitor p27 Kip1 gene directly. Also, we have shown that HER2 promotes mitogenic growth and transformation of cancer cells by downregulation of p27 Kip1. Given the fact that FOXO4 mediates p27 transcription, we hypothesize that an Akt phosphorylation mutant of FOXO4 (FOXO4A3), which maintains the activity to transactivate p27 Kip1, may be used as an anticancer agent for HER2-overexpressing cancers. Here, we applied the FOXO4 gene as a novel anticancer agent for HER2-overexpressing cells under the control of a tetracycline (tet)-regulated gene expression system. Overexpression of FOXO4A3 inhibits HER2-activated cell growth. We found that FOXO4A3 inhibited the kinase activity of protein kinase B/Akt and reversed HER2-mediated p27 mislocation in the cytoplasm. FOXO4A3 expression also led to decreased levels of CSN5, a protein involved in p27 degradation. These data suggest that FOXO4A3 also can regulate p27 post-transcriptionally. In addition, we found that FOXO4A3 sensitized cells to apoptosis induced by the chemotherapeutic agent 2-methoxyestradiol. Most significantly for clinical application, FOXO4A3 expression in HER2-overexpressing cells can be regulated in vivo and reduces the tumor volume in a tumor model. These findings indicate the applicability of employing FOXO4 regulation as a therapeutic intervention in HER2-overexpressing cancers.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/AKT1 protein, human, http://linkedlifedata.com/resource/pubmed/chemical/CDKN1B protein, human, http://linkedlifedata.com/resource/pubmed/chemical/Carrier Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Cyclin D1, http://linkedlifedata.com/resource/pubmed/chemical/Cyclin-Dependent Kinase Inhibitor..., http://linkedlifedata.com/resource/pubmed/chemical/FOXO4 protein, human, http://linkedlifedata.com/resource/pubmed/chemical/Intracellular Signaling Peptides..., http://linkedlifedata.com/resource/pubmed/chemical/Protein-Serine-Threonine Kinases, http://linkedlifedata.com/resource/pubmed/chemical/Proto-Oncogene Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Proto-Oncogene Proteins c-akt, http://linkedlifedata.com/resource/pubmed/chemical/Transcription Factors
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0950-9232
pubmed:author
pubmed:issnType
Print
pubmed:day
10
pubmed:volume
24
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1924-35
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed-meshheading:15688030-3T3 Cells, pubmed-meshheading:15688030-Animals, pubmed-meshheading:15688030-Carrier Proteins, pubmed-meshheading:15688030-Cell Line, pubmed-meshheading:15688030-Cell Transformation, Neoplastic, pubmed-meshheading:15688030-Cyclin D1, pubmed-meshheading:15688030-Cyclin-Dependent Kinase Inhibitor p27, pubmed-meshheading:15688030-Genes, erbB-2, pubmed-meshheading:15688030-Humans, pubmed-meshheading:15688030-Intracellular Signaling Peptides and Proteins, pubmed-meshheading:15688030-Kidney, pubmed-meshheading:15688030-Mice, pubmed-meshheading:15688030-Protein Processing, Post-Translational, pubmed-meshheading:15688030-Protein-Serine-Threonine Kinases, pubmed-meshheading:15688030-Proto-Oncogene Proteins, pubmed-meshheading:15688030-Proto-Oncogene Proteins c-akt, pubmed-meshheading:15688030-Transcription Factors
pubmed:year
2005
pubmed:articleTitle
Constitutively active FOXO4 inhibits Akt activity, regulates p27 Kip1 stability, and suppresses HER2-mediated tumorigenicity.
pubmed:affiliation
Department of Molecular and Cellular Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't