Phosphodiesterase specific inhibitors control cell growth of a human neuroepithelioma cell line

The effects of cyclic nucleotide phosphodiesterase (PDE) inhibitors on cell proliferation of SK-N-MC human neuroepithelioma cell line was studied. Clonal density experiments in the presence of 100 microM rolipram and zaprinast showed respectively 27% and 91% inhibition. The effects of PDE inhibitors were then investigated on crude cell extracts; the calculated IC50 were 32 microM for zaprinast and 16 nM for DC-TA-46; the latter inhibitor was used instead of rolipram for its higher efficacy. Dose-response experiments in clonal density conditions showed IC50 of 5 microM and 1.8 microM in the presence respectively of zaprinast and rolipram. These data show that both inhibitors are effective in reducing cell growth, although the response was quantitatively different.