Linked Life Data

8665514

Source:http://linkedlifedata.com/resource/pubmed/id/8665514

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
12
pubmed:dateCreated
1996-8-6
pubmed:abstractText
There is strong evidence to suggest that insulin and insulin-like growth factor (IGF)-I may be important for tumor growth. Both the insulin and IGF-I receptors (IGF-IR) are overexpressed in breast cancer, and antibody blockade of the IGF-IR inhibits the growth of some breast cancer cell lines. Furthermore, expression of an insulin receptor (IR) in a normal mammary epithelia] cell line causes insulin-dependent transformation. Functional inactivation of p53 is also very frequent in many tumors. In this paper, we investigated whether inactivation of p53 might be involved in the overexpression of the IR in malignancy, specifically breast cancer. We demonstrate a positive correlation between IR and IGF-IR levels and p53 overexpression in primary human breast malignancies. To examine possible mechanisms by which p53 may regulate IR gene expression, we show that p53 can repress the IR promoter and that a dominant-negative p53 (248Q) can de-repress the promoter in cells containing normal p53. The p53 effect was shown to be mediated by C/EBP and Sp1 transcription factors. We also documented that p53-null mice had elevated levels of Sp1, but not C/EBPalpha, and that insulin binding to liver extracts was increased compared to wild-type controls. These results suggest that p53 inactivation may lead to an up-regulation of genes, such as the IR, that are dependent on these transcription factors.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0008-5472
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
56
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2781-8
pubmed:dateRevised
2011-11-17
pubmed:meshHeading
pubmed-meshheading:8665514-Animals, pubmed-meshheading:8665514-Base Sequence, pubmed-meshheading:8665514-Binding, Competitive, pubmed-meshheading:8665514-Breast Neoplasms, pubmed-meshheading:8665514-CCAAT-Enhancer-Binding Proteins, pubmed-meshheading:8665514-DNA-Binding Proteins, pubmed-meshheading:8665514-Female, pubmed-meshheading:8665514-Genes, Reporter, pubmed-meshheading:8665514-Humans, pubmed-meshheading:8665514-Insulin, pubmed-meshheading:8665514-Insulin-Like Growth Factor I, pubmed-meshheading:8665514-Mice, pubmed-meshheading:8665514-Molecular Sequence Data, pubmed-meshheading:8665514-Nuclear Proteins, pubmed-meshheading:8665514-Promoter Regions, Genetic, pubmed-meshheading:8665514-Receptor, IGF Type 1, pubmed-meshheading:8665514-Receptor, Insulin, pubmed-meshheading:8665514-Sp1 Transcription Factor, pubmed-meshheading:8665514-Transfection, pubmed-meshheading:8665514-Tumor Suppressor Protein p53
pubmed:year
1996
pubmed:articleTitle
Repression of the insulin receptor promoter by the tumor suppressor gene product p53: a possible mechanism for receptor overexpression in breast cancer.
pubmed:affiliation
Department of Medicine, Division of Endocrinology and Metabolism, University of California, San Diego, La Jolla, California 92093, 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