AKT plays a central role in mediating cAMP inhibitory effects in DLBCL. (A) AKT phosphorylation in DHL6-parental or DHL6-PDE4B-WT cells treated with forskolin/rolipram. DHL6-parental or DHL6-PDE4B-WT cells were incubated with 40 μM forskolin and 10 μM rolipram for the specified time periods, and cell lysates were harvested and immunoblotted for pAKT (Ser 473) and total AKT as loading control. The Figure 4D filter was stripped and reprobed for pAKT and total AKT in this experiment. (B) Proliferation of forskolin-treated DHL6-eGFP, DHL6-Myr-AKT-WT, and DHL6-Myr-AKT-MAA cells. The indicated cells were incubated with 10 μM forskolin for 24 hours and cell proliferation was determined by MTS assay. Data represent the mean and SD of 3 independent experiments. (C) Total and phospho-AKT expression in DHL6-eGFP, DHL6-Myr-AKT-WT, and DHL6-Myr-AKT-MAA cells in the presence or absence of forskolin. The indicated cells were incubated with 10 μM forskolin for 15 minutes and cell lysates immunoblotted for pAKT (Ser 473) and total AKT. (D) AKT phosphorylation in PDE4B-high cell lines DHL7, OCI-Ly3, and OCI-Ly10. Cell lines were preincubated with 20 μM PLX513 for 30 minutes followed by treatment with 40 μM forskolin for the specified time periods and cell lysates were harvested and immunoblotted for pAKT.