Regulation of growth-regulated oncogene α expression by estrogen in human endothelial cells

AIM: To study the effect of estrogen on expression of growth-regulated oncogene alpha (GRO alpha) in human umbilical vein endothelial cells (HUVEC) in vitro. METHODS: Expressions of CXC chemokine GRO alpha mRNA and protein were measured by Northern blotting assay and ELISA, respectively. The physiological significance of GRO alpha expression was tested by static cell adhesion assay. RESULTS: Both the GRO alpha mRNA and protein levels decreased markedly after HUVEC were exposured to 17 beta -estradiol (E-2) 0.05 mu mol/L. Moreover, the inhibition of the protein was depended on the concentration of 17 beta -estradiol. Tamoxifen (0.1 mu mol/L), an estrogen receptor a antagonist, alone did not affect GRO alpha protein expression, but can reverse the E-2-induced inhibition of GRO alpha protein expression ( by up to 50 %) and the binding of U937 cells to E-2-treated HUVEC (by up to 40 %). CONCLUSION: Estrogen might functionally down-regulates GRO alpha expression through estrogen receptor a on endothelial cells.