Estrogen binding, receptor mRNA, and biologic response in osteoblast-like osteosarcoma cells.
High specific activity estradiol labeled with iodine-125 was used to detect approximately 200 saturable, high-affinity (dissociation constant approximately equal to 1.0 nM) nuclear binding sites in rat (ROS 17/2.8) and human (HOS TE85) clonal osteoblast-like osteosarcoma cells. Of the steroids tested, only testosterone exhibited significant cross-reactivity with estrogen binding. RNA blot analysis with a complementary DNA probe to the human estrogen receptor revealed putative receptor transcripts of 6 to 6.2 kilobases in both rat and human osteosarcoma cells. Type I procollagen and transforming growth factor-beta messenger RNA levels were enhanced in cultured human osteoblast-like cells treated with 1 nM estradiol. Thus, estrogen can act directly on osteoblasts by a receptor-mediated mechanism and thereby modulate the extracellular matrix and other proteins involved in the maintenance of skeletal mineralization and remodeling.
Komm
B S
BS
Department of Biochemistry, University of Arizona College of Medicine, Tucson 85724.
Terpening
C M
CM
Benz
D J
DJ
Graeme
K A
KA
Gallegos
A
A
Korc
M
M
Greene
G L
GL
O'Malley
B W
BW
Haussler
M R
MR
D000818:Animals; D001667:Binding, Competitive; D002467:Cell Nucleus / Q000378:metabolism; D004247:DNA / Q000235:genetics; D004958:Estradiol / Q000378:metabolism* / Q000494:pharmacology; D006801:Humans; D007457:Iodine Radioisotopes; D009693:Nucleic Acid Hybridization; D010006:Osteoblasts / Q000187:drug effects / Q000378:metabolism*; D012516:Osteosarcoma / Q000378:metabolism*; D010455:Peptides / Q000235:genetics; D011347:Procollagen / Q000235:genetics; D012333:RNA, Messenger / Q000378:metabolism*; D051381:Rats; D011960:Receptors, Estrogen / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic; D015291:Transforming Growth Factors; D014407:Tumor Cells, Cultured
D007457:Iodine Radioisotopes; D010455:Peptides; D011347:Procollagen; D012333:RNA, Messenger; D011960:Receptors, Estrogen; D004958:Estradiol; D015291:Transforming Growth Factors; D004247:DNA