Investigation On The Expression And Relative Mechanism Of CGMP Dependent Protein Kinase Ⅱ In Cancer Cells

ObjectiveTo detect the difference of expression and activity of cGMP dependent protein kinase II (PKG II) in normal cell, transformed cell lines and cancer cell lines with same tissue origine, to investigate the related mechanism, and to study the effects of the PKGII on regulation of gene expression.Methods(1) Transformed cell lines and cancer cell lines with the identical tissue origine were chosen and reverse transcription PCR was used to detect the expression of PKGII mRNA in the cells.(2) Transformed cell lines and cancer cell lines with the identical tissue origine were chosen and Western blotting was used to detect the expression of PKGII protein in the cells.(3) 8-pCPT-cGMP was used to activate PKGII, Western blotting was applied to detect the phosphorylation of PKG II substrate vasodilator-stimulated phosphoprotein (VASP) to represent the activity of the kinase.(4) The sequence of promoter region of PKG II gene was cloned from human Gastric Cancer Cell line SGC-7901 cells and the sequence was analyzed.(5)Choose representative cell, transfect the cells with plasmid encoding PKGII, then used 8-pCPT-cGMP to activate PKGII; fluorescence differential display was used to detect the effects of PKGII on the regulation gene expression.Results (1) In rat and human tissue derived cell lines, the expression of PKGII mRNA in transformed cell lines was higher than that of cancer cell lines.(2) In rat and human tissue derived cell lines, the expression of PKGII protein in transformed cell lines was higher than that of cancer cell lines.(3) In rat and human tissue derived cell lines, the phosphorylation level of VASP in transformed cell lines was higher than that of cancer cell lines. It indicated that the activity of PKG II in transformed cell lines was higher than that of cancer cell lines.(4) In human Gastric Cancer Cell line SGC-7901, the promoter region of PKG II gene had basyl mutation.(5) In representative cell, PKGII had no obvious effects on regulation gene expression.ConclusionIn the condition of the identical source, expression and activity of PKGII in cancer cell lines were lower than those of cancer cell lines; In human Gastric Cancer Cell line SGC-7901 cell, the promoter region of PKG II gene had basyl mutation; PKGII had no obvious effects on regulation of gene expression.