Di Francesco P, Pica F, Favalli C, Tubaro E, Garaci E
Department of Experimental Medicine and Biochemical Sciences II, University of Rome, Tor Vergata, Italy.
Cell Biol Int Rep. 1990 Jun;14(6):549-58. doi: 10.1016/0309-1651(90)91182-4.
We have analyzed the role of cocaine in the control of the rat fibroblast (EL2) cell proliferation. Our data show a dose-related effect on the inhibition of DNA synthesis and cell growth when cocaine is added with serum or with a pure growth factor [Epidermal Growth Factor (EGF)]. Pretreatment by drug did not appreciably enhance the inhibition of S-phase entry above that obtained when cocaine and mitogen were added simultaneously. On the contrary, exposure of quiescent EL2 cells to cocaine has little or no effect on DNA synthesis, when drug is removed before the mitogenic stimulus. Moreover, even when cocaine is added after EGF, an exposure only within 1-8 hours is required in order to inhibit stimulation of DNA synthesis. Cocaine also suppressed the general increase in protein synthesis that occurs during the first hour after EGF addition. The combined data suggest that cocaine inhibits the traverse of mitogen-stimulated quiescent EL2 cells from Go to S phase by acting on processes that take place during the initial phase of the cell cycle.
我们分析了可卡因在控制大鼠成纤维细胞（EL2）增殖中的作用。我们的数据表明，当可卡因与血清或纯生长因子[表皮生长因子（EGF）]一起添加时，对DNA合成和细胞生长的抑制具有剂量相关效应。药物预处理并没有比可卡因和促有丝分裂原同时添加时明显增强对S期进入的抑制作用。相反，当在促有丝分裂刺激之前去除药物时，静止的EL2细胞暴露于可卡因对DNA合成几乎没有影响。此外，即使在EGF之后添加可卡因，为了抑制DNA合成的刺激，仅需要在1-8小时内暴露。可卡因还抑制了添加EGF后第一小时内发生的蛋白质合成的总体增加。综合数据表明，可卡因通过作用于细胞周期初始阶段发生的过程，抑制有丝分裂原刺激的静止EL2细胞从G0期到S期的转变。
