Linked Life Data

7626488

Source:http://linkedlifedata.com/resource/pubmed/id/7626488

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1-6
pubmed:dateCreated
1995-9-7
pubmed:abstractText
The evaluation of estrogens (estrone, estradiol, and their sulfates) in the breast tissue of post-menopausal patients with breast cancer indicates high levels, particularly of estrone sulfate (E1S) which is 15-25 times higher than in the plasma. Breast cancer tissue contains the enzymes necessary for local synthesis of estradiol and it was demonstrated that, despite the presence of the sulfatase and its messenger in hormone-dependent and hormone-independent breast cancer cells, this enzyme operates particularly in hormone-dependent cells. Different progestins: Nomegestrol acetate, Promegestone, progesterone, as well as Danazol, can block the conversion of E1S to E2 very strongly in hormone-dependent breast cancer cells. The last step in the formation of estradiol is the conversion of E1 to this estrogen by the action of 17 beta-hydroxysteroid dehydrogenase. This activity is preferentially in the reductive direction (formation of E2) in hormone-dependent cells, but oxidative (E2-->E1) in hormone-independent cells. Using intact hormone-dependent cells it was observed that Nomegestrol acetate can block the conversion of E1 to E2. It is concluded, firstly, that in addition to ER mutants other factors are involved in the transformation of hormone-dependent breast cancer to hormone-independent, this concerns the enzymatic activity in the formation of E2; it is suggested that stimulatory or repressive factor(s) involved in the enzyme activity are implicated as the cancer evolves to hormone-independence; secondly, different drugs can block the conversion of E1S to E2. Clinical trials of these "anti-enzyme" substances in breast cancer patients could be the next step to investigate new therapeutic possibilities for this disease.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0960-0760
pubmed:author
pubmed:issnType
Print
pubmed:volume
53
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
407-12
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1995
pubmed:articleTitle
Estrone sulfate-sulfatase and 17 beta-hydroxysteroid dehydrogenase activities: a hypothesis for their role in the evolution of human breast cancer from hormone-dependence to hormone-independence.
pubmed:affiliation
C.N.R.S. Steroid Hormone Research Unit, Foundation for Hormone Research, Paris, France.
pubmed:publicationType
Journal Article, In Vitro, Research Support, Non-U.S. Gov't