IL-7 suppresses the transactivation of a promoter driven by six OSE2 elements and blunts Cbfa1/Runx2 promoter activity in ROS 17/2.8 osteoblastic cells. (a) p6OSE2-luc, a luciferase reporter construct driven by six tandem copies of OSE2 fused to a minimal OCN promoter, and p6OSE2mut-luc, a control construct containing six inactive OSE2 sites, were transfected into ROS 17/2.8 osteoblastic cells, and luciferase activity was assessed at 24 hours in unstimulated cells and cells stimulated with IL-7 (10 ng/ml). Data are shown as average ± SD of triplicate cultures and are representative of three independent experiments. *P < 0.05 (t test). (b) pGL3–Cbfa1/Runx2, a luciferase reporter construct containing the distal OB-specific Cbfa1/Runx2 promoter (–620 bp), or empty vector (pGL3-basic) was transfected into ROS 17/2.8 osteoblastic cells, and luciferase activity was assessed at 24 hours in unstimulated cells and cells stimulated with IL-7 (10 ng/ml). The data are shown as average ± SD of triplicate cultures and are representative of three independent experiments. *P < 0.05 (t test).