Cyclic AMP inhibits mitogen‐induced DNA synthesis in hamster fibroblasts, regardless of the signalling pathway involved

FEBS Letters

Paris, Sonia¹  Pouysségur, Jacques¹  Magnaldo, Isabelle¹ 

[1] Centre de Biochimie du CNRS, Faculté des Sciences, Parc Valrose, Université de Nice, 06034 Nice Cédex, France

关键词: DNA synthesis;    cyclic AMP;    Growth factor;    (Hamster fibroblast);    FGF;    fibroblast growth factor;    IBMX;    3-isobutyl-l-methylxanthine;   

DOI  :  10.1016/0014-5793(89)80193-0

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Mitogen-induced initiation of DNA synthesis in quiescent Chinese hamster lung fibroblasts (CCL39) is strongly inhibited by 8-Br cAMP and cAMP-elevating agents (prostaglandin E₁, cholera toxin, isobutylmethylxanthine). This inhibition is reversible and occurs very early in G₀/G₁. As exponential growth is much less affected by increased cAMP, we propose that cAMP inhibits an early signal essential for the exit from G₀. CCL39 cells can be stimulated by α-thrombin, which activates phosphoinositide (PI) ]breakdown, as well as by mitogens (FGF or FGF+serotonin) which do not involve the PI pathway. Here we show that the action of both classes of mitogens is likewise inhibited by cAMP. Therefore, although PI breakdown is inhibited by cAMP in CCL39 cells, this effect cannot entirely account for the antimitogenic activity of cAMP. Other early steps of the mitogenic response must be also affected.

【 授权许可】

Unknown