title: Effects of estriol on proliferative activity and expression of insulin-like growth factor-I (IGF-I) and IGF-I receptor mRNA in cultured human osteoblast-like osteosarcoma cells.
abstract: The present study was undertaken to elucidate whether estriol (E3) affects the proliferative activity and the expression of insulin-like growth factor-I (IGF-I) mRNA and IGF-I receptor (IGF-IR) mRNA in cultured human osteoblast-like osteosarcoma cells (HOS TE85). In this study, the effects of E3 on cultured HOS TE85 cells were compared with those of 17 beta-estradiol (E2). HOS TE85 cells were subcultured in phenol red-free Dulbecco's modified Eagle's medium supplemented with 10% fetal bovine serum for 72 h and then stepped down to serum-free conditions for an additional 72 h in the absence or presence of E3 (3.52 x 10(-9), 3.52 x 10(-8), 3.52 x 10(-7) mol/l) or E2 (3.67 x 10(-8) mol/l). Treatment with either E3 (3.52 x 10(-8), 3.52 x 10(-7) mol/l) or E2 (3.67 x 10(-8) mol/l) resulted in an increase in the number of cultured HOS TE85 cells and their uptake of bromodeoxyuridine. Northern blot hybridization with a IGF-I cDNA probe revealed that RNA prepared from cultured HOS TE85 cells contained IGF-I mRNA transcripts of 1.8, 4.4 and 7.5 kb. Treatment with either E3 (3.52 x 10(-9), 3.52 x 10(-8), 3.52 x 10(-7) mol/l) or E2 (3.67 x 10(-8) mol/l) resulted in increased expression of the three mRNA transcripts relative tot hose in untreated control cultures. Semi-quantitative, reverse transcription polymerase chain reaction analysis showed that the 440-bp IGF-IR mRNA transcript was present in HOS TE85 cells and that treatment with either E3 or E2 did not affect the IGF-IRmRNA expression in these cells. These results demonstrate that E3 (3.52 x 10(-9), 3.52 x 10(-8), 3.52 x 10(-7) mol/l) exerts profound effects on the proliferative potential of cultured HOS TE85 cells, compatible with that of E2 (3.67 x 10(-8) mol/l), through the induction of IGF-I mRNA expression without affecting IGF-IR mRNA expression in these cells.
authors.affiliation: Department of Obstetrics and Gynecology, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Shinsuke
authors.initials: S
authors.lastname: Mochizuki
authors.forename: Shigeki
authors.initials: S
authors.lastname: Yoshida
authors.forename: Yoshihiko
authors.initials: Y
authors.lastname: Yamanaka
authors.forename: Hiroya
authors.initials: H
authors.lastname: Matsuo
authors.forename: Takeshi
authors.initials: T
authors.lastname: Maruo
mesh_terms: D001973:Bromodeoxyuridine / Q000378:metabolism; D049109:Cell Proliferation / Q000187:drug effects*; D004958:Estradiol / Q000494:pharmacology; D004964:Estriol / Q000494:pharmacology*; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000096:biosynthesis / Q000187:drug effects*; D010006:Osteoblasts / Q000187:drug effects / Q000502:physiology; D012516:Osteosarcoma / Q000503:physiopathology*; D012333:RNA, Messenger / Q000096:biosynthesis / Q000187:drug effects; D017526:Receptor, IGF Type 1 / Q000096:biosynthesis / Q000187:drug effects*; D014407:Tumor Cells, Cultured
chemical_list: D012333:RNA, Messenger; D004958:Estradiol; D007334:Insulin-Like Growth Factor I; D017526:Receptor, IGF Type 1; D004964:Estriol; D001973:Bromodeoxyuridine