The effect of parathyroid hormone on osteogenic activities of human osteosarcoma cell line SaOS-2

Objective To observe the effects of recombinant human parathyroid hormone 1 to 34(referred to as hPTH) on the expression level of alkaline phosphatase(ALP) and bone gla protein(BCP) in human osteosarcoma cell line SaOS-2(referred to as SaOS-2 cells). Methods SaOS-2 cells were subcultured and treated with 1, 10 and 100 nmol/L hPTH for 12, 24 and 48 h. Total cellular RNA was extracted, cDNA was synthesized by reverse doses of hPTH, different duration of action, and their interaction on the expression level of ALP mRNA of SaOS-2 cells was significantly different(F = 29.32, 2.92, 7.64, all P < 0.05). The expression level of ALP mRNA(0.78 ± 0.43, 0.71 ± 0.05, 0.75 ± 0.19, 0.76 ± 0.14) of SaOS-2 cells after treatment with 0, 1, 10 and 100 nmol/L hPTH for 48 h was lower than those of treated for 12 h(1.01 ± 0.16, 1.37 ± 0.38, 1.49 ± 0.16, 2.52 ± 0.70, all P< 0.05) and 24 h (1.80 ± 0.47, 1.30 ± 0.36, 1.27 ± 0.17, 1.17 ± 0.11, all P< 0.05). The expression level of ALP mRNA of SaOS-2 cells after treatment with 100 nmol/L hPTH for 12 hours was higher than that of the control(P < 0.05); the expression level of ALP mRNA of SaOS-2 cells after treatment with 1, 10 and 100 nmol/L hPTH for 24 h interaction on the expression level of BGP mRNA of SaOS-2 were significantly different (F = 8.26, 10.33, 5.51, all P< 0.05). The expression level of BGP mRNA(1.17 ± 0.28, 0.98 ± 0.08, 0.92 ± 0.17 and 0.84 ± 0.59) of SaOS2 cells after treatment with 0, 1, 10 and 100 nmol/L hPTH for 48 h was lower than those of treated for 12 h( 1.01 ± 0.14, 1.21 ± 0.18, 1.34 ± 0.30, 1.68 ± 0.62, all P< 0.05), and 24 h(1.71 ± 0.35, 1.41 ± 0.47, 1.28 ± 0.31 and 1.01 ± 0.18, all P < 0.05). The expression level of BGP mRNA of SaOS-2 cells after treatment with 100 nmol/L hPTH for 12 h was higher than that of those groups treated with 0 and 1 nmol/L hPTH(all P< 0.05). The expression level of BGP mRNA of SaOS-2 cells after treatment with 10 and 100 nmol/L hPTH for 24 h and 48 h was lower than those of the control(all P < 0.05). The expression level of BGP mRNA of SaOS-2 cells after treatment with 100 nmol/L hPTH for 24 hours was lower than that the group treated with 1 nmol/L hPTH(P < 0.05). Conclusions In vitro, hPTH significantly enhances osteogenic activities of human osteoblast in a short time, however, with prolonged stimulation time, osteogenic activity can show a downward trend. Key words: Teriparatide;  Osteoblasts;  Alkaline phosphatase;  Osteocalcin