TY - JOUR
T1 - Estrogenic and antiestrogenic activities of 16α- and 2-hydroxy metabolites of 17β-estradiol in MCF-7 and T47D human breast cancer cells
AU - Gupta, Mona
AU - McDougal, Andrew
AU - Safe, Stephen
N1 - Funding Information:
The financial assistance of the National Institutes of Health (ES04176) and the Texas Agricultural Experiment Station is gratefully acknowledged. S. Safe is a Sid Kyle Professor of Toxicology.
PY - 1998
Y1 - 1998
N2 - The comparative mitogenic activities of 17β-estradiol (E2) and four metabolites, 2-hydroxyestradiol (2-OHE2), 2-hydroxyestrone (2-OHE1), 16α- hydroxyestradiol (16α-OHE2) and 16α-hydroxyestrone (16α-OHE1) were determined in estrogen receptor (ER)-positive MCF-7 and T47D human breast cancer cells. E2 (1 nM) induced a 7- to 13-fold increase in cell number in both cell lines compared to untreated cells and the mitogenic potencies of 16α-OHE1 or 16α-OHE2 were comparable to or greater than E2. In contrast, 2- OHE1 and 2-OHE2 were weak mitogens in both cell lines and in cells cotreated with 1 nM E2 and 100 or 1000 nM 2-OHE1 or 2-OHE2, there was a significant inhibition of hormone-induced cell proliferation. The comparative ER agonist/antagonist activities of E2 and the metabolites on transactivation were determined in T47D cells transiently transfected with constructs containing promoter inserts from the cathepsin D (pCD) and creatine kinase B (pCKB) genes. E2, 16α-OHE2 and 16α-OHE1 induced reporter gene activity in both MCF-7 or T47D cells transfected with pCKB or pCD. In contrast, 2-OHE1 and 2-OHE2 did not exhibit ER agonist activity for these transactivation assays, but in cells cotreated with E2 plus 2-OHE1 or 2-OHE2, there was a significant decrease in the hormone-induced response. These results demonstrate that 16α-OHE1/16α-OHE2 exhibit estrogenic activities similar to that observed for E2, whereas the 2-catecholestrogens are weak ER agonists (cell proliferation) or antagonists (cell proliferation and transactivation).
AB - The comparative mitogenic activities of 17β-estradiol (E2) and four metabolites, 2-hydroxyestradiol (2-OHE2), 2-hydroxyestrone (2-OHE1), 16α- hydroxyestradiol (16α-OHE2) and 16α-hydroxyestrone (16α-OHE1) were determined in estrogen receptor (ER)-positive MCF-7 and T47D human breast cancer cells. E2 (1 nM) induced a 7- to 13-fold increase in cell number in both cell lines compared to untreated cells and the mitogenic potencies of 16α-OHE1 or 16α-OHE2 were comparable to or greater than E2. In contrast, 2- OHE1 and 2-OHE2 were weak mitogens in both cell lines and in cells cotreated with 1 nM E2 and 100 or 1000 nM 2-OHE1 or 2-OHE2, there was a significant inhibition of hormone-induced cell proliferation. The comparative ER agonist/antagonist activities of E2 and the metabolites on transactivation were determined in T47D cells transiently transfected with constructs containing promoter inserts from the cathepsin D (pCD) and creatine kinase B (pCKB) genes. E2, 16α-OHE2 and 16α-OHE1 induced reporter gene activity in both MCF-7 or T47D cells transfected with pCKB or pCD. In contrast, 2-OHE1 and 2-OHE2 did not exhibit ER agonist activity for these transactivation assays, but in cells cotreated with E2 plus 2-OHE1 or 2-OHE2, there was a significant decrease in the hormone-induced response. These results demonstrate that 16α-OHE1/16α-OHE2 exhibit estrogenic activities similar to that observed for E2, whereas the 2-catecholestrogens are weak ER agonists (cell proliferation) or antagonists (cell proliferation and transactivation).
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U2 - 10.1016/S0960-0760(98)00135-6
DO - 10.1016/S0960-0760(98)00135-6
M3 - Article
C2 - 10030690
AN - SCOPUS:0032448464
SN - 0960-0760
VL - 67
SP - 413
EP - 419
JO - Journal of Steroid Biochemistry and Molecular Biology
JF - Journal of Steroid Biochemistry and Molecular Biology
IS - 5-6
ER -