Koch K S, Lu X P, Leffert H L
Department of Pharmacology, University of California San Diego, La Jolla 92093.
Biochem Biophys Res Commun. 1994 Oct 14;204(1):91-7. doi: 10.1006/bbrc.1994.2430.
Cyclin D1 messenger RNA expression was investigated in differentiated proliferation-competent primary cultures of adult rat hepatocytes. Periodic expression was observed during the 12-day growth cycle (approximately two population doublings). Upon reaching a quiescent G(o)-state, 4-kb cyclin D1 mRNA levels were undetectable. When G(o) cultures were shifted into defined media without or with 0.2-0.8 nM TGF-alpha, conditions that reinitiate full proliferative transitions synchronously, cyclin D1 mRNA levels were elevated 1.2-4.6-fold, respectively. These findings support the hypothesis that hepatic mitogens stimulate periodic cyclin mRNA expression directly.
在成年大鼠肝细胞具有增殖能力的分化原代培养物中研究了细胞周期蛋白D1信使核糖核酸（mRNA）的表达。在12天的生长周期（约两个群体倍增）中观察到周期性表达。当进入静止的G（0）期时，无法检测到4kb细胞周期蛋白D1 mRNA水平。当将处于G（0）期的培养物转移到不含或含有0.2 - 0.8 nM转化生长因子α（TGF-α）的限定培养基中时（这两种条件均可同步重新启动完全增殖转变），细胞周期蛋白D1 mRNA水平分别升高了1.2 - 4.6倍。这些发现支持了肝有丝分裂原直接刺激周期性细胞周期蛋白mRNA表达这一假说。
