Poster Presenter

Characterization of cAMP Related Phosphodiestearase in Mouse Skin Malignant Melanoma B16 Cells
Yoshihiro Watanabe, Taku Murata, Kasumi Shimizu, Hiroshi Morita, Takashi Takeoka, Jouji Nomura, Toshiro Tagawa
Japan

Background: Phosphodiesterases (PDEs) regulate the intracellular concentrations of cAMP and/or cGMP by catalyzing their hydrolysis, and participate in various physiological functions in normal cells. PDEs represent 11 gene families (PDE1 to PDE11). Some PDE families are relatively specific for cAMP or for cGMP; others hydrolyze both. Previously we reported cAMP related PDE1 and PDE4 expression in B16 cells. However, little is known about other cAMP related PDEs. In this study, we examined the expression of cAMP related PDEs ( PDE2, PDE7, PDE10 and PDE11), PDE2 activity and the effect of PFE7 inhibitor on cell growth in B16 cells.

Methods: Cells: Mouse B16 melanoma. The expressions of PDE mRNAs were ascertained by RT-PCR. PDE2 activity was examined by cAMP-PDE activity assay with PDE2 specific inhibitor. The cells were cultured with cAMP-analog (8-Bromo-cAMP) or PDE7 inhibitor for 6 days. Then, the cell numbers were calculated.

Results: The expressions of PDE7, PDE10 and PDE11 mRNA were detected. PDE2 activity and expression were not detected. Growth of B16 cells was inhibited by 8-Bromo-cAMP, but not PDE7 inhibitor, in a dose dependent manner.

Conclusion: Our results suggested that PDE10 and/or PDE11 may play an important role in the cell growth of B16 cells.