TY - JOUR
T1 - Determination of estradiol2- and 16-alpha-hydroxylase activities in MCF-7 human breast cancer cells in culture using radiometric analysis
AU - Niwa, Toshifumi
AU - Bradlow, H. Leon
AU - Fishman, Jack
AU - Swaneck, George E.
N1 - Funding Information:
- L1I LldiscusslionT. he exce llen tte chnicaal ssistancoef Mrs Heshla cant EZ study was supportedi n part by grants HD19825 and Ash and Mr OsamuS assai s gratefullya cknowledgedT.h is
PY - 1989/8
Y1 - 1989/8
N2 - Using a radiometric assay the effects of estradiol upon the activity of estradiol 2- and 16α-hydroxylases in MCF-7 human breast cancer cells in culture were studied. After 5 days of treatment and 36 h of withdrawal, incubation in the presence of either 2- or 16α-tritiated substrate was carried out. Estradiol (10 nM) significantly increased 16α-hydroxylase activity (21%, P < 0.01), while no effects on 2-hydroxylase activity was observed. Treatment for 6 weeks caused a major increase in 16α-hydroxylation (65%, P < 0.001) and a significant reduction in 2-hydroxylation (21%, P < 0.05). These effects were not observed in estrogen receptor-negative MDA-MB-231 human breast cancer cells. Our observations suggest that these two metabolic pathways in MCF-7 cells are independently regulated and that this regulation is affected via the estrogen receptor.
AB - Using a radiometric assay the effects of estradiol upon the activity of estradiol 2- and 16α-hydroxylases in MCF-7 human breast cancer cells in culture were studied. After 5 days of treatment and 36 h of withdrawal, incubation in the presence of either 2- or 16α-tritiated substrate was carried out. Estradiol (10 nM) significantly increased 16α-hydroxylase activity (21%, P < 0.01), while no effects on 2-hydroxylase activity was observed. Treatment for 6 weeks caused a major increase in 16α-hydroxylation (65%, P < 0.001) and a significant reduction in 2-hydroxylation (21%, P < 0.05). These effects were not observed in estrogen receptor-negative MDA-MB-231 human breast cancer cells. Our observations suggest that these two metabolic pathways in MCF-7 cells are independently regulated and that this regulation is affected via the estrogen receptor.
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U2 - 10.1016/0022-4731(89)90309-9
DO - 10.1016/0022-4731(89)90309-9
M3 - Article
C2 - 2770303
AN - SCOPUS:0024710043
VL - 33
SP - 311
EP - 314
JO - Journal of Steroid Biochemistry
JF - Journal of Steroid Biochemistry
SN - 0960-0760
IS - 2
ER -
