Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2008-2-18
pubmed:abstractText
Inactivation of cellular p53 is a crucial step in carcinogenesis. Accordingly, p53 is inactivated in most human cancers by different mechanisms. In cells infected with DNA tumor viruses, p53 is bound to the viral tumor antigens (Tag). The current "dogma" views the Tag-p53 complexes as a way of sequestering and inactivating p53. Using primary human cells and SV40-transformed human cells, we show that in addition to inactivating p53 tumor suppressor activities, the Tag-p53 complex has growth stimulatory activities that are required for malignant cell growth. We found that in human cells, Tag-p53 complexes regulate transcription of the insulin-like growth factor I (IGF-I) gene by binding to the IGF-I promoter together with pRb and p300. Depletion of p53 leads to structural rearrangements of this multiprotein complex, resulting in IGF-I promoter transcriptional repression and growth arrest. Our data provide a novel mechanistic and biological interpretation of the p53-Tag complexes and of DNA tumor virus transformation in general. In the model we propose, p53 is not a passive inactive partner of Tag. Instead the p53-Tag complex promotes malignant cell growth through its ability to activate the IGF-I signaling pathway.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
1538-7445
pubmed:author
pubmed:issnType
Electronic
pubmed:day
15
pubmed:volume
68
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1022-9
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed-meshheading:18281476-Animals, pubmed-meshheading:18281476-Antigens, Polyomavirus Transforming, pubmed-meshheading:18281476-Astrocytes, pubmed-meshheading:18281476-Cell Growth Processes, pubmed-meshheading:18281476-Cell Transformation, Neoplastic, pubmed-meshheading:18281476-Down-Regulation, pubmed-meshheading:18281476-Epithelial Cells, pubmed-meshheading:18281476-Humans, pubmed-meshheading:18281476-Insulin-Like Growth Factor I, pubmed-meshheading:18281476-Oncogene Proteins, Viral, pubmed-meshheading:18281476-Promoter Regions, Genetic, pubmed-meshheading:18281476-Protein Binding, pubmed-meshheading:18281476-Rats, pubmed-meshheading:18281476-Receptor, IGF Type 1, pubmed-meshheading:18281476-Recombinant Proteins, pubmed-meshheading:18281476-Repressor Proteins, pubmed-meshheading:18281476-Signal Transduction, pubmed-meshheading:18281476-Transduction, Genetic, pubmed-meshheading:18281476-Tumor Suppressor Protein p53
pubmed:year
2008
pubmed:articleTitle
The SV40 large T antigen-p53 complexes bind and activate the insulin-like growth factor-I promoter stimulating cell growth.
pubmed:affiliation
Department of Pathology and Oncology Institute, Loyola University Chicago, Cancer Center, Maywood, Illinois 60153, USA. mbocche@lumc.edu
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't, Research Support, N.I.H., Extramural