Regulation of endogenous IGFBP1 gene expression in H4IIE cells following C/EBPα overexpression. H4IIE cells were infected with adenovirus expressing either β-Galactosidase (AD-βgal) or Flag-C/EBPα (Ad-C/EBPα). Infected cells were serum starved overnight prior to a 3 h incubation with insulin (10 nM), dexamethasone (500 nM), CHIR99021 (CT, 2 μM), or a combination of each as indicated. RNA was extracted and IGFBP1 expression was measured by RPA. Expression was calculated relative to cyclophilin mRNA levels. Data are presented as the average ± SEM of three experiments, with a representative autoradiograph shown in the upper panels.