RhoA蛋白和cAMP对人前列腺癌细胞株PC-3形态的影响(简报)

小G蛋白RhoA是细胞内信号转导的重要成分,参与对细胞的多种功能活动的调控。溶血磷脂酸(lysophosphatidicacid,LPA)与多种细胞的G蛋白偶连受体结合而发挥作用,除刺激细胞增殖外,还通过活化RhoA,诱导细胞骨架改变。cAMP是经典的第二信使,其下游激酶PKA可抑制RhoA活性,因此,cAMP在许多细胞活动中对RhoA有拮抗作用。本实验采用人前列腺癌细胞株PC-3,以绿色荧光蛋白(GreenFluorescentProtein,GFP)分别和不同RhoA结构(野生型RhoA、RhoA63L和RhoA188A)的cDNA共同转染细胞,在显微镜下(200倍视野)观察记录未转染细胞和转染细胞在LPA和cAMP作用下的形态变化,研究RhoA和cAMP/PKA介导的信号转导在调控癌细胞形态改变中的作用。

EFFECT OF RhoA AND cAMP ON MORPHOLOGICAL CHANGES IN HUMAN PROSTATE CANCER CELL LINE PC-3

This paper was designed to investigate the effect of RhoA and cAMP/PKA mediat- ing signal transduction on the morphological changes of human prostate cancer cell line PC-3. Different RhoA cDNA expressing constructs were used to transfect PC-3 cells. Transfected and untransfected cells were stimulated with lysophosphatidic acid(LPA) and/or cAMP. The morphologi- cal changes of the cells were recorded by inversive microscope. Results showed that the untrans- fected cells changed their conformation from polygonal to round with the stimulation of LPA,while cAMP prevented the change. LPA caused the same change in cells transfected with wild type, constitutively active type and 188 mutant of RhoA. cAMP prevented the change in cells transfect- ed with wild type and constitutively active RhoA but not in cells transfected with 188 mutant of RhoA. The results suggested that cAMP/PKA could inhibit the morphological effect of RhoA through phosphorylating RhoA on 188 serine.