Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2004-7-7
pubmed:abstractText
Increased risk of developing endometrial cancers has been observed in women treated with tamoxifen (TAM), a widely used drug for breast cancer therapy and chemoprevention. The carcinogenic effect may be due to genotoxic DNA damage induced by TAM. In fact, TAM-DNA adducts were detected in the endometrium of women treated with this drug. TAM is alpha-hydroxylated by cytochrome P450 3A4 followed by O-sulfonation by hydroxysteroid sulfotransferase, and reacts with guanine residues in DNA, resulting in the formation of alpha-(N2-deoxyguanosinyl)tamoxifen adducts. During this metabolic process, short-lived carbocations are produced at the ethyl moiety of TAM as reactive intermediates. TAM-DNA adducts promote primarily G -->T transversions in mammalian cells. The same mutations have been frequently detected at codon 12 of the K-ras gene in the endometrial tissue of women treated with this drug. TAM-DNA adducts, if not readily repaired, may act as initiators, leading to development of endometrial cancers. The reactivity of TAM metabolites with DNA is inhibited in toremifene, where the hydrogen atom has been replaced by a chlorine atom at the ethyl moiety. Therefore, toremifene may be a safer alternative to TAM. This article describes an overview of the mechanism of TAM-DNA adduct formation, mutagenic events of this adduct, and detection of TAM-DNA adducts in the endometrium of women treated with TAM.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0360-2532
pubmed:author
pubmed:issnType
Print
pubmed:volume
36
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
199-218
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2004
pubmed:articleTitle
Genotoxic mechanism of tamoxifen in developing endometrial cancer.
pubmed:affiliation
Laboratory of Chemical Biology, Department of Pharmacological Sciences, State University of New York at Stony Brook, Stony Brook, New York 11794-8651, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Review