van Grunsven L A, Thomas A, Urdiales J L, Machenaud S, Choler P, Durand I, Rudkin B B
Laboratoire de Biologie Moléculaire et Cellulaire, Ecole Normale Supérieure de Lyon, France.
Oncogene. 1996 Feb 15;12(4):855-62.
The anti-proliferative effect of nerve growth factor (NGF) on the rat pheochromocytoma cell line PC12 has been previously shown to be accompanied by the accumulation of cells in either the G1 phase with a 2c DNA content, or with a 4c DNA content characteristic for G2/M, as evidenced by flow cytometric analysis of DNA distribution using propidium iodide. Herein, these apparently conflicting results are clarified. The present studies indicate that a simple DNA distribution profile obtained by this technique can confound interpretation of the biological effects of NGF on cell-cycle distribution due to the presence of tetraploid cells. Using cyclin D1 and incorporation of bromodeoxyuridine as markers of respectively, G1 and S phase, we show that PC12 cultures can have a considerable amount of tetraploid cells which, when in the G1 phase, have a 4c DNA content and express cyclin D1. During exposure to NGF, this population increases, reflecting the accumulation of cells in the G1 phase of the cell cycle. The data presented, support the possibility that events affecting the expression or action of G1 regulatory proteins may be involved in the molecular mechanism of the anti-mitogenic effect of NGF.
神经生长因子（NGF）对大鼠嗜铬细胞瘤细胞系PC12的抗增殖作用先前已表明伴随着细胞在G1期（DNA含量为2c）或具有G2/M期特征的4c DNA含量的积累，这通过使用碘化丙啶对DNA分布进行流式细胞术分析得以证明。在此，这些明显相互矛盾的结果得到了澄清。目前的研究表明，由于四倍体细胞的存在，通过该技术获得的简单DNA分布图谱可能会混淆对NGF对细胞周期分布的生物学效应的解释。分别使用细胞周期蛋白D1和溴脱氧尿苷掺入作为G1期和S期的标志物，我们表明PC12培养物中可能有相当数量的四倍体细胞，当它们处于G1期时，具有4c DNA含量并表达细胞周期蛋白D1。在暴露于NGF期间，这一群体增加，反映了细胞在细胞周期G1期的积累。所呈现的数据支持这样一种可能性，即影响G1调节蛋白表达或作用的事件可能参与了NGF抗有丝分裂作用的分子机制。
