Estradiol increases the production of sex hormone-binding globulin but notinsulin-like growth factor binding protein-1 in cultured human hepatoma cells

Objective: To study the effects of E-2 on insulin-like growth factor bindin g protein-1 (IGFBP-1) and sex hormone-binding globulin (SHBG) production wi th cultured human HepG2 hepatoma cells. Design: Experimental cell culture. Setting: Academic medical center. Patient(s): None. Intervention(s): Addition of E-2 to cell culture medium. Main Outcome Measure(s): Intracellular and released concentrations of IGFBP -1 and SHBG. Result(s): Estradiol did not affect the intracellular or extracellular IGFB P-1 concentration, whereas the intracellular SHBG concentration increased s ignificantly in response to 0.5-2.5 mu M of E-2. Conclusion(s): Whereas the two binding proteins share a number of regulator y factors, their regulation by E-2 is dissimilar in human hepatoma cells. E stradiol does not affect the intracellular or secreted IGFBP-1 concentratio n, but it does increase the production of SHBG. (C) 1999 by American Societ y for Reproductive Medicine.