Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
36
pubmed:dateCreated
2009-9-10
pubmed:abstractText
We identified a somatic mutation in estrogen receptor-alpha (ERalpha) in breast cancer causing a lysine to arginine transition (K303R) resulting in hypersensitivity to estrogen, altered associations with coactivators and corepressors and altered posttranslational modifications of ERalpha. We have developed a transgenic mouse expressing the K303R mutant ERalpha under control of the mouse mammary tumor virus (MMTV) promoter. At 4 months of age, K303R ERalpha transgenic animals demonstrate precocious alveolar budding compared with wild-type ERalpha transgenic mice or nontransgenic littermates. Despite these morphologic differences, K303R ERalpha transgenic mice displayed no differences in levels of ERalpha, progesterone receptor or proliferation at this time-point. Pregnancy or chronic estrogen plus progesterone exposure in K303R ERalpha transgenic mice also resulted in significantly more alveolar budding, increased beta-casein production and dilated ducts when compared with nontransgenic littermates. To examine the effects of mutant expression on tumorigenesis, mutant ERalpha mice were crossed with FVB-MMTVneu mice and significantly delayed time to neu-mediated tumorigenesis in bigenic animals. In contrast, mutant expression did not affect carcinogen-induced tumorigenesis. Collectively, these data demonstrate that aberrant estrogenic signaling through the K303R ERalpha mutation may lead to precocious alveolar budding in virgin mice, and to an expedited maturation and differentiation phenotype in the mammary glands of hormonally stimulated animals.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
1476-5594
pubmed:author
pubmed:issnType
Electronic
pubmed:day
10
pubmed:volume
28
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
3177-87
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed-meshheading:19561644-Amino Acid Substitution, pubmed-meshheading:19561644-Animals, pubmed-meshheading:19561644-Cell Differentiation, pubmed-meshheading:19561644-Cell Proliferation, pubmed-meshheading:19561644-Estrogen Receptor alpha, pubmed-meshheading:19561644-Estrogens, pubmed-meshheading:19561644-Female, pubmed-meshheading:19561644-Immunohistochemistry, pubmed-meshheading:19561644-Male, pubmed-meshheading:19561644-Mammary Glands, Animal, pubmed-meshheading:19561644-Mammary Neoplasms, Experimental, pubmed-meshheading:19561644-Mammary Tumor Virus, Mouse, pubmed-meshheading:19561644-Mice, pubmed-meshheading:19561644-Mice, Transgenic, pubmed-meshheading:19561644-Mutation, pubmed-meshheading:19561644-Pregnancy, pubmed-meshheading:19561644-Progesterone, pubmed-meshheading:19561644-Promoter Regions, Genetic, pubmed-meshheading:19561644-Rats, pubmed-meshheading:19561644-Receptor, erbB-2, pubmed-meshheading:19561644-Receptors, Progesterone, pubmed-meshheading:19561644-Reverse Transcriptase Polymerase Chain Reaction
pubmed:year
2009
pubmed:articleTitle
Accelerated mammary maturation and differentiation, and delayed MMTVneu-induced tumorigenesis of K303R mutant ERalpha transgenic mice.
pubmed:affiliation
Lester and Sue Smith Breast Center, Baylor College of Medicine, Houston, TX 77030, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S., Research Support, N.I.H., Extramural