cAMP signaling increases GR expression and activity and potentiates dexamethasone-induced gene expression. (A-D) Analysis of NR3C1 mRNA and total and Ser-211 phosphorylated NR3C1 protein levels in (A-B) CUTLL1 or (C-D) KOPTK1 cells treated with vehicle, dexamethasone (1 μM), forskolin (10 µM), and IBMX (100 μM) designated F/I or dexamethasone + F/I for 2, 4, 6, and 8 hours. (E-F) qPCR analysis of NR3C1 target genes in CUTLL1 (E) and KOPTK1 (F) cells treated as indicated for 24 hours. All qPCR values were normalized to vehicle-treated cells. The results are averages of 3 independent experiments, and error bars represent SEM. *P < .05, **P < .01, ***P < .001.