Linked Life Data

2219196

Source:http://linkedlifedata.com/resource/pubmed/id/2219196

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
7
pubmed:dateCreated
1990-11-1
pubmed:abstractText
The effects of estradiol, progesterone, and tamoxifen on the activity of estradiol 2- and 16 alpha-hydroxylases were studied in human breast cancer cell cultures using a radiometric assay. After 5 days' exposure to these compounds, incubations in the presence of either [2-3H]estradiol or [16 alpha-3H]estradiol as substrate were carried out. In MCF-7 cells, estradiol (10(-8) M), progesterone (10(-6) M) and tamoxifen (10(-6) M) significantly increased 16 alpha-hydroxylase activity (estradiol; 21% progesterone 10% to 32%; tamoxifen 21% to 31%; P less than 0.01). Synergistic effects were observed when the cells were successively exposed to tamoxifen and progesterone. Simultaneous treatment with tamoxifen plus estradiol or estradiol plus progesterone showed no change from estradiol alone. On the other hand, although estradiol had no direct effects on 2-hydroxylase activity, tamoxifen decreased this enzymatic activity significantly at 10(-6) M (23% to 37%). Progesterone acted synergistically to further decrease this reaction. Treatment with only progesterone caused an increase in 2-hydroxylation. In contrast, a subline of MCF-7 cells with low estrogen receptor levels showed only minimal enzyme-hormone responses. Likewise, treatment of the estrogen receptor-negative MDA-MB-231 human breast cancer cell line with these compounds showed no effects on either 2- or 16 alpha-hydroxylase activity. In the progesterone receptor-rich T47D cell line, estradiol decreased both activities while progesterone increased both.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/Aryl Hydrocarbon Hydroxylases, http://linkedlifedata.com/resource/pubmed/chemical/Cytochrome P-450 CYP1A1, http://linkedlifedata.com/resource/pubmed/chemical/Cytochrome P-450 Enzyme System, http://linkedlifedata.com/resource/pubmed/chemical/Estradiol, http://linkedlifedata.com/resource/pubmed/chemical/Progesterone, http://linkedlifedata.com/resource/pubmed/chemical/Receptors, Estrogen, http://linkedlifedata.com/resource/pubmed/chemical/Receptors, Progesterone, http://linkedlifedata.com/resource/pubmed/chemical/Steroid 16-alpha-Hydroxylase, http://linkedlifedata.com/resource/pubmed/chemical/Steroid Hydroxylases, http://linkedlifedata.com/resource/pubmed/chemical/Tamoxifen, http://linkedlifedata.com/resource/pubmed/chemical/estrogen 2-hydroxylase
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0039-128X
pubmed:author
pubmed:issnType
Print
pubmed:volume
55
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
297-302
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1990
pubmed:articleTitle
Induction and inhibition of estradiol hydroxylase activities in MCF-7 human breast cancer cells in culture.
pubmed:affiliation
Laboratory of Biochemical Endocrinology, Rockefeller University, New York, New York.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.