Nice View of CleanEx Exp : GSE4025_DOC

[General] [References] [Expression data]

General information about the entry
Dataset code GSE4025
Dataset Title Gene Expression Preferentially Regulated by Tamoxifen in Breast Cancer Cells
Description The beneficial effect of the selective estrogen receptor modulator (SERM) tamoxifen in the treatment and prevention of breast cancer is assumed to be through its ability to antagonize the stimulatory actions of estrogen, although tamoxifen can also have some estrogen-like agonist effects. Here we report that in addition to these mixed agonist/antagonist actions, tamoxifen can also selectively regulate a unique set of more than 60 genes in estrogen receptor alpha (ERa)-positive MCF-7 human breast cancer cells which are minimally regulated by estradiol or raloxifene. This gene regulation by tamoxifen is mediated by ERa and is reversed by estradiol or ICI 182,780. We find that the introduction of ERbeta into MCF-7 cells reverses tamoxifen action on approximately 75% of these genes, suggesting that ERbeta is capable of repressing certain actions of tamoxifen. To examine whether these genes might serve as markers of tamoxifen sensitivity and/or the development of resistance, the expression level of these genes was examined in breast tumors of women who had received treatment with tamoxifen. High expression of two of the tamoxifen stimulated genes, YWHAZ/14-3-3z and LOC441453, was found to correlate significantly with disease recurrence following tamoxifen treatment in women with ER-positive tumors, and hence appear to be markers of a poor prognosis. Our data indicate a new dimension in tamoxifen action, involving gene expression regulation that is tamoxifen-preferential, and identify genes that might serve as markers of tumor responsiveness or resistance to tamoxifen therapy..
Organism Homo sapiens
Format Type Intensity
Number of Experiments 17
Maximum log 10.429704799721
Minimum log -3.64644293964961
Original URL
Paper Reference Frasor J et al. Cancer Res. 2006 Jul 15;66(14):7334-40.
MEDLINE Reference 16849584
Experiment numberExperiment CodeExperiment Description
1GSE4025_GSM92147Ad+veh replicate1 b;Ad(moi10)-infected, vehicle-treated";
2GSE4025_GSM92148Ad+veh replicate2 b;Ad(moi10)-infected, vehicle-treated";
3GSE4025_GSM92149Ad+E2 replicate1 b;Ad(moi10)-infected, E2-treated";
4GSE4025_GSM92150Ad+E2 replicate2 b;Ad(moi10)-infected, E2-treated";
5GSE4025_GSM92151Ad+E2 replicate3;Ad(moi10)-infected, E2-treated";
6GSE4025_GSM92152Ad+TOT replicate1;Ad(moi10)-infected, TOT-treated";
7GSE4025_GSM92153Ad+TOT replicate2;Ad(moi10)-infected, TOT-treated";
8GSE4025_GSM92154Ad+TOT replicate3;Ad(moi10)-infected, TOT-treated";
9GSE4025_GSM92155AdERb +veh replicate1;AdERb(moi10)-infected, veh-treated";
10GSE4025_GSM92156AdERb +veh replicate2;AdERb(moi10)-infected, veh-treated";
11GSE4025_GSM92157AdERb +veh replicate3;AdERb(moi10)-infected, veh-treated";
12GSE4025_GSM92158AdERb +E2 replicate1;AdERb(moi10)-infected, E2-treated";
13GSE4025_GSM92159AdERb +E2 replicate2;AdERb(moi10)-infected, E2-treated";
14GSE4025_GSM92160AdERb +E2 replicate3;AdERb(moi10)-infected, E2-treated";
15GSE4025_GSM92161AdERb +TOT replicate1;AdERb(moi10)-infected, TOT-treated";
16GSE4025_GSM92162AdERb +TOT replicate2;AdERb(moi10)-infected, TOT-treated";
17GSE4025_GSM92163AdERb +TOT replicate3;AdERb(moi10)-infected, TOT-treated";