Fig. 4: Knockdown of PDE4DIP induces PKA-CREB signalling activation in NSCLC cells.

A Western blot analysis of PDE4DIP-mediated signalling pathway components in control and PDE4DIP-KD NSCLC cells. B Western blot analysis of CREB phosphorylation and downstream target gene expression in NSCLC cells overexpressing PDE4DIP (PI). Cells were transfected with the PDE4DIP expression plasmid for 48 h, and the pCDNA3.1 empty vector was used as a control (Vec). C Western blot showing that treatment with the PKA inhibitor H89 blocked PDE4DIP KD-induced PKA signalling activation and alterations in downstream target gene expression. Cells were transduced with shRNAs for 72 h and were then treated with either 10 µM H89 or DMSO for 24 h. (D) qRT‒PCR analysis of Bim and RB1 mRNA expression in control and PDE4DIP overexpressing H1299 and A549 cells. ***P < 0.001 vs. Control (PI). E qRT‒PCR analysis results showing that treatment with H89 blocked PDE4DIP KD-induced upregulation of Bim and RB1 mRNA expression. ***P < 0.001 vs. shNC.