Linked Life Data

12376470

Source:http://linkedlifedata.com/resource/pubmed/id/12376470

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
10
pubmed:dateCreated
2002-10-11
pubmed:abstractText
The oxidative metabolites of estrogen have been proposed to play an important role in the development of some human cancers. The two major pathways of estrogen metabolism, to the carcinogenic 4-hydroxyestradiol (4-OHE2) and to the non-carcinogenic 2-hydroxyestradiol (2-OHE2), are mediated by cytochromes P450 CYP1B1 and CYP1A1, respectively. The expression of CYP1A1 and CYP1B1 is regulated by the aromatic hydrocarbon receptor/Ah receptor nuclear translocator (AhR/ARNT) transcription factor complex. CYP1B1 expression is elevated in a wide range of human cancers but is not found in corresponding normal tissue. Thioredoxin-1 (Trx-1) is a small redox protein that is overexpressed in a number of human cancers. We report that the expression of CYP1B1 mRNA and protein is increased by Trx-1 transfection of MCF-7 human breast cancer cells and decreased by a redox inactive mutant Trx-1. The Trx-1 inhibitor PX-12 inhibits CYP1B1 gene expression. Trx-1 transfected MCF-7 cells show increased AhR/ARNT DNA binding activity that is not due to altered AhR or ARNT protein expression. 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD, dioxin) induced expression of CYP1B1 in MCF-7 cells is increased by Trx-1. Trx-1 does not effect the basal expression of CYP1A1, but increases CYP1A1 mRNA in response to TCDD. The redox inactive mutant Trx-1 completely blocks the induction of both CYP1B1 and CYP1A1 by TCDD. Expression of CYP1A1 but not CYP1B1 has been linked to estrogen receptor (ERalpha) status. Trx-1 transfected MCF-7 cells have decreased ERalpha expression, which may account for the lack of CYP1A1 induction by Trx-1 in the absence of ligand. The results suggest that Trx-1 is involved in the constitutive expression of CYP1B1 and is required for the induction of CYP1B1 and CYP1A1 by TCDD in human MCF-7 breast cancer cells.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0143-3334
pubmed:author
pubmed:issnType
Print
pubmed:volume
23
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1625-30
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
2002
pubmed:articleTitle
The redox protein thioredoxin-1 regulates the constitutive and inducible expression of the estrogen metabolizing cytochromes P450 1B1 and 1A1 in MCF-7 human breast cancer cells.
pubmed:affiliation
Arizona Cancer Center, University of Arizona, 1515 N. Campbell Avenue, Tucson, AZ 85724-5024, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.