RT Journal Article
SR Electronic
T1 Effects of the Antiestrogens Tamoxifen and Raloxifene on the Estrogen Receptor Transactivation Machinery
JF Anticancer Research
JO Anticancer Res
FD International Institute of Anticancer Research
SP 735
OP 744
VO 26
IS 1B
A1 GLAESER, MICHAEL
A1 NIEDERACHER, DIETER
A1 DJAHANSOUZI, SIRUS
A1 HANSTEIN, BETTINA
A1 DITTRICH, RALF
A1 BECKMANN, MATTHIAS W.
A1 FASCHING, PETER A.
A1 ACKERMANN, SVEN
YR 2006
UL http://ar.iiarjournals.org/content/26/1B/735.abstract
AB The influence of 17β-estradiol (E2), tamoxifen (TAM) and raloxifen (RLX) on the proliferation of breast (BC) and endometrial carcinoma cell lines (EC) and the expression of different compounds of the estrogen receptor (ER)-transactivation machinery were studied. E2 stimulated the proliferation of BC, but had no effect on the EC. TAM showed a biphasic effect on ER-positive cell lines. RLX showed an antagonistic suppression or no effect. The expression of ERα was down-regulated by E2, but not affected by selective estrogen receptor modulators. ERβ and progesterone receptor expressions were up-regulated by E2, TAM and OHT. This supports the hypothesis that ERβ expression is also regulated via the ERα-pathway. The steroid receptor coactivator (SRC) AIB1 expression was slightly decreased by E2 but not by antiestrogens (antiE). TIF2 expression was increased by E2, TAM and RLX, but SRC-1 expression was not. In comparison, the expressions of ERβ and progesterone receptor were strongly influenced by antiE, while the expression of SRCs was only slightly affected. Copyright© 2006 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved