Objectives: Pancreatic cancer is one of the leading causes of cancer related deaths in the western world. It is also resistant to most chemotherapeutic modalities. Phosphodiesterase-4 inhibitors (PDE4is) have found applications in the treatment of respiratory diseases. The aim of this study is to investigate the cytotoxic effect of 2 novel PDE4is, the CC-8075 and CC-8062 compounds in pancreatic cancer cells.
Methods: Cell proliferation was measured using the sulforhodamine B protein dye. Induction of apoptosis was detected using enzyme-linked immunosorbent assay. Regulation of proteins and posttranslational modifications were determined using immunoblotting.
Results: Treatment of pancreatic cancer cells with CC-8075 and CC-8062 reduces their proliferation and increases apoptosis that is caspase dependent in T3M4 cells. Furthermore, PDE4is increase phosphorylation of p38MAPK, mitogen-activated protein kinase (MAPK) kinase 3/6,MAPKYactivated protein kinase 2, Atf2, and Hsp27. The use of thep38MAPK-specific inhibitors SB202190 and SB203580 results in a modest reduction in PDE4i-induced apoptosis in T3M4 cells. Also, retinoids enhance apoptosis induced by CC-8075 and CC-8062 in GER cells.
Conclusions: These results highlight the antiproliferative effects of the phosphodiesterase inhibitors CC-8075 and CC-8062 in pancreatic cancer cells and suggest that activation of p38MAPK signaling pathway may be associated with this process.