ESTROGEN AND PARATHYROID HORMONE REGULATE INSULIN-LIKE GROWTH FACTOR BINDING PROTEIN-4 IN SAOS-2 CELLS

摘要

The effect of 17 beta-estradiol and parathyroid hormone (PTH) on the expression of insulin-like growth factor-binding protein-4 (IGFBP-4) messenger:RNA (mRNA) was studied in the cultured human osteoblast-like SaOS-2 cells. Treatment of SaOS-2 cells with PTH for 3 h caused 3.3-fold increase in IGFBP-4 mRNA levels which was determined by reverse transcription-polymerase chain reaction. 17 beta-Estradiol had no effect on either the stimulation of mRNA level by PTH or the basal level. Together with our previous report that 17 beta-estradiol inhibits the PTH-induced reduction of IGFBP-4 proteolysis in these cells, the results obtained may help to explain the mechanisms of determining IGFBP-4 availability by systemic hormones in osteoblast cells. [References: 19]