cGMP依赖性蛋白激酶Ⅱ在癌细胞株中的表达及活性

Expression of cGMP dependent protein kinaseⅡ in cancer cell lines was obviously decreased

目的:探讨cGMP依赖性蛋白激酶Ⅱ(cGMP dependent protein kinaseⅡ,PKGⅡ)在相同组织来源的正常细胞、转化细胞和癌细胞中的表达及活性的差异。方法:选择相同组织来源的正常细胞、转化细胞株和癌细胞株,通过逆转录PCR和Western blotting分别检测PKGⅡmRNA和蛋白表达水平,用Western blotting检测PKGⅡ底物血管扩张刺激磷蛋白(vasodilator-stimulated phosphoprotein,VASP)的磷酸化以反映PKGⅡ的活性。结果:在大鼠和人胃来源的细胞株中,PKGⅡ在转化细胞中表达较高,而在癌细胞的表达明显降低;与之对应的是,PKGⅡ在癌细胞的活性明显低于转化细胞。结论:在相同组织来源的情况下,与转化细胞相比,PKGⅡ在肿瘤细胞中的表达和活性较低。

Objective： To investigate the difference of expression and activity of cGMP dependent protein kinase Ⅱ （PKG Ⅱ ）in normal cell from the same tissue, and in transformed cell lines and cancer cell lines. Methods： Tranformed cell lines and cancer cell lines with the identical source were chosen and reverse transcription PCR and Western blotting were used to detect the expression of PKG Ⅱ in both mRNA and protein level. Western blotting was applied to the phosphorylation of PKG Ⅱ substrate vasodilator-stimulated phosphoprotein（VASP） to represent the activity of the kinase. Results： In rat and human tissue derived cell lines, expression of PKG Ⅱ in transformed cell lines was higher than that of cancer cell lines. Correspondingly, the activity of PKG Ⅱ in transformed cell lines was higher than that of cancer cell lines. Conclusion： In the condition of the identical source, expression and activity of PKG Ⅱ in cancer cell lines were lower than those of transformed cell lines.