Linked Life Data

9443065

Source:http://linkedlifedata.com/resource/pubmed/id/9443065

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1998-2-12
pubmed:abstractText
It has been suggested that there is a positive correlation between increased incidence of breast cancer and the presence of organochlorine residues such as DDT and HCH in breast tissues in the United States. To study possible biochemical links between these two parameters, we have examined the effect of o,p'-DDT, the most estrogenic congener of the DDT family of chemicals and beta-HCH on protein phosphorylation activities in MCF-7, a line derived from human breast cancer cells. Both of these organochlorine chemicals were found to be potent activators of protein kinases. Among kinases activated, protein tyrosine kinases (PTK) appear to be most affected as judged by the antagonistic action of genistein, a class-specific PTK inhibitor. Moreover, these organochlorines were found to activate PTK even under cell-free conditions, indicating that they are likely to interact directly with the target protein tyrosine kinase. As a result of immunoprecipitation with specific antibodies, and testing on the action of these organochlorines, we could show that the major kinase activated by o,p'-DDT is c-Neu (= c-erbB2 product protein). The concentrations of these organochlorines required to activate c-Neu were extremely low (0.1-1 nM range), whereas an inactive analog p,p'-DDT showed no stimulatory property even at 100 nM. Such an action of these organochlorine compounds were not antagonized by the presence of 1 microM tamoxifen, indicating that it is not mediated through the estrogen receptor. In addition, their c-Neu activating actions were specifically antagonized by a c-Neu antibody known to interact with the extracellular domain of c-Neu only without affecting the EGF receptor. Moreover, these chemicals did not cause downregulation of the EGF receptor during the 72 hour test period. Together these data indicate that the action of these chemicals on c-Neu kinase is very specific.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
1095-6670
pubmed:author
pubmed:issnType
Print
pubmed:volume
12
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
83-92
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
Activation of c-Neu tyrosine kinase by o,p'-DDT and beta-HCH in cell-free and intact cell preparations from MCF-7 human breast cancer cells.
pubmed:affiliation
Department of Environmental Toxicology, University of California, Davis 95616, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S.