Effect of 1,25(OH)2D3 on expression of estrogen receptor-alpha mRNA on rat osteosarcoma cell line (ROS 17/2.8).
In order to investigate the regulatory mechanisms of estrogen receptors (ER) in bone cells, changes in ER-alpha mRNA levels of rat osteosarcoma cell line (ROS 17/2.8) before and after exposure to 1,25(OH)2D3 and 17-beta estradiol respectively were measured by quantitative polymerase chain reaction using an internal standard. ER mRNA levels in the ROS 17/2.8 cultured with the medium alone had 5.029 +/- 1.623 mol/g total RNA x 10(-13) and were not statistically different from those cultured in the presence of 1,25(OH)2D3 at concentrations of 10(-12) M and less. ER mRNA levels in the ROS 17/2.8 cell line showed a small but a significant increase as a result of stimulation by 1,25(OH)2D3 at concentrations of 10(-10) and 10(-11) M. However, ER mRNA levels in ROS 17/2.8 cultured in the presence of 1,25(OH)2D3 at concentrations of 10(-9) M were not statistically different from those of the control. On the other hand, the expression of ER in ROS 17/2.8 cells cultured for 3 hours with various doses of 1,25(OH)2D3 showed, by immunoblotting methods, a significant increase at the dose of 10(-10) M in the expression of ER. Although a physiological significance is obscure, these observations suggest that 1,25(OH)2D3 plays a part in the expression of ER in ROS 17/2.8. No significant changes were seen in the expression of ER mRNA and the synthesis of ER as a result of stimulation by the estradiol.
Ohsawa
M
M
Department of Obstetrics and Gynecology, Gunma University School of Medicine, Maebashi, Japan.
Mizunuma
H
H
Kagami
I
I
Miyamoto
S
S
Kanuma
T
T
Ibuki
Y
Y
D000818:Animals; D047628:Estrogen Receptor alpha; D004967:Estrogens / Q000494:pharmacology*; D015870:Gene Expression / Q000187:drug effects; D012516:Osteosarcoma / Q000378:metabolism* / Q000473:pathology; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D011960:Receptors, Estrogen / Q000096:biosynthesis* / Q000187:drug effects / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013250:Steroid Hydroxylases / Q000494:pharmacology*; D014407:Tumor Cells, Cultured
D047628:Estrogen Receptor alpha; D004967:Estrogens; D012333:RNA, Messenger; D011960:Receptors, Estrogen; D013250:Steroid Hydroxylases; C406322:vitamin D 1-alpha hydroxylase