Type â…¡ CGMP-dependent Protein Kinase Inhibits Proliferation MAPK/ERK Signaling Of Gastric Cancer Cell Line

ObjectiveTo construct a recombinant adenoviral vector encoding cGMP dependent protein kinaseâ…¡(PKGâ…¡) gene,study the effect of PKGâ…¡on proliferation-related MAPK signal transduction,and study the effects of the PKGâ…¡on regulation of gene expression.Methods(1) Constructing a recombinant adenovirus vector encoding cGMP dependent protein kinaseâ…¡(PKGâ…¡) gene according to the protocol from Invitrogen.(2) Adenoviral construct encoding PKGâ…¡gene(Ad-PKGâ…¡) was used to infect BGC-823 cells,AGS cells and SGC-7901 cells. 8-pCPT-cGMP was used to activate PKGâ…¡.Western blotting was applied to detect the phosphorylation(activation) of Ras,Raf and ERK(the key components of MAPK signal transduction pathway).(3) Infected BGC-823 cells with adenoviral construct encoding PKGâ…¡gene(Ad-PKGâ…¡),then used 8-pCPT-cGMP to activate PKGâ…¡; Fluorescence differential display was used to detect the differences of PKGâ…¡on the regulation gene expression.Results(1) A remcombinant adenoviral vector encoding PKGâ…¡was successfully constructed.(2) In BGC-823 cells,AGS cells and SGC-7901 cells,activation of PKGâ…¡by 8-pCPT-cGMP significantly inhibited the EGF induced phosphorylation(activation) of ERK.(3) In BGC-823 cells,AGC cells and SGC-7901 cells,activation of PKGâ…¡by 8-pCPT-cGMP significantly inhibited the EGF induced phosphorylation(activation) of Raf.(4) In BGC-823 cells and SGC-7901 cells,activation of PKGâ…¡by 8-pCPT-cGMP significantly inhibited the EGF induced activation of Ras.(5) In BGC-823 cells,PKGâ…¡had no obvious effects on regulation gene expression.ConclusionIn gastric cancer cells,increase of expression and activity of PKGâ…¡significantly inhibited MAPK signaling through inhibiting phosphorylation(activation) of Ras,Raf and ERK(the key components of MAPK signal transduction pathway);PKGâ…¡had no obvious effects on regulation of gene expression.