cis-tamoxifen behaved as a weak estrogen agonist in all assays , while trans-tamoxifen was an effective estrogen antagonist . cis-tamoxifen behaved like estradiol in stimulating mcf-7 cell growth and increasing plasminogen activator activity and cellular progesterone receptor content , although very much higher concentrations of cis-tamoxifen ( 10 ( -6 ) m ) were needed to achieve the levels of stimulation observed with 10 ( -10 ) m estradiol . trans-tamoxifen and trans-hydroxytamoxifen suppressed cell growth , inhibited plasminogen activator activity of control cells , and suppressed estradiol-stimulation of plasminogen activator activity , and they evoked minimal increases in cellular progesterone receptor levels . trans-hydroxytamoxifen had a 100-fold increased affinity for er and was approximately 100-times more potent than was trans-tamoxifen in suppressing cell growth and plasminogen activator activity . cis-hydroxytamoxifen behaved as an estrogen antagonist , suppressing cell growth and plasminogen activator activity , and it elicited submaximal increases in progesterone receptor levels .
C0007634
cellular
C0007595
cell growth