EFFECT OF NORMAL-BUTYRATE ON CELL-CYCLE PROGRESSION AND IN SITU CHROMATIN STRUCTURE OF L1210 CELLS
EFFECT OF NORMAL-BUTYRATE ON CELL-CYCLE PROGRESSION AND IN SITU CHROMATIN STRUCTURE OF L1210 CELLS
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DOI：
10.1016/0014-4827(81)90006-9
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发表时间：
1981-01-01
影响因子：
3.7
通讯作者：
MELAMED, MR
中科院分区：
文献类型：
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作者：
DARZYNKIEWICZ, Z;TRAGANOS, F;MELAMED, MR
在1-5 mM正丁酸盐的存在下，鼠白血病L1210细胞停止增殖并停滞在G1期的G1 A区室中。与G1期（G1 B）的剩余细胞相比，该隔室中的细胞的特征在于低RNA含量和更浓缩的染色质。在无干扰生长期间，细胞在G1 A中的停留时间是不确定的持续时间（指数分布）; L1210细胞在G1 A中停留的半衰期约为1.4 h。正丁酸对G1 A期细胞的阻滞作用呈浓度依赖性。L1210细胞经12 h以上的药物处理后，对该药物的敏感性明显增强。停滞在G1 A期的细胞仍然存活，当去除正丁酸盐时，经过一段滞后期后，它们恢复了整个周期的进展。在稳态动力学实验中研究了正丁酸盐对细胞通过周期的各个部分的进展的影响。在1、2.5和5 mM正丁酸盐存在下，细胞进入有丝分裂的速率分别降低了30、60和110%，表明细胞通过G2和S的进展减慢。在1，2.5和5 mM的正丁酸，分别延长了20，70和140%的G2的持续时间。通过1、2.5和5 mM正丁酸盐，细胞在G1 A中停留的半衰期增加多达1.5- 6.3和15.6倍。在1 mM浓度下，G1晚期（G1 B）的进展不受影响，并且在更高的药物浓度下无法估计。对细胞周期进程的影响是明显的1小时后，加入正丁酸。正丁酸盐处理的细胞核中的原位DNA降低（2 - 8 ℃）。C）对热变性的稳定性和对DNA酶I的可接近性增加（增加15%）。当在1 mM MgCl 2而不是EDTA存在下加热渗透细胞时，DNA对热的稳定性降低更明显。DNA原位在正丁酸处理的细胞的细胞核中也表现出降低敏感性酸诱导变性。在添加正丁酸盐后1小时内，在所有细胞中均观察到染色质变化，无论细胞周期阶段如何。有丝分裂细胞比间期细胞对正丁酸的反应更迅速。在L1210细胞中观察到的变化最有可能是正丁酸盐诱导的组蛋白修饰（内部组蛋白的乙酰化，组蛋白H1的去磷酸化）的结果。
In the presence of 1-5 mM n-butyrate, murine leukemic L1210 cells cease proliferation and become arrested in the G1A compartment of the G1 phase. Cells in this compartment, in comparison with the remaining cells of the G1 phase (G1B), are characterized by low RNA content and more condensed chromatin. During unperturbed growth the cell residence times in G1A are of indeterminate duration (exponentially distributed); the half-time of L1210 cell residence in G1A is about 1.4 h. The effect of n-butyrate in arresting cells in G1A was concentration-dependent. The sensitivity of L1210 cells to this drug was markedly enhanced when cels were treated for longer than 1 generation (12 h). Cells arrested in G1A remained viable and when n-butyrate was removed, after a lag period, they resumed progression through the cycle. The effect of n-butyrate on cell progression through various parts of the cycle was studied in a stathmokinetic experiment. The rate of cell entrance into mitosis was decreased by 30, 60 and 110%, in the presence of 1, 2.5 and 5 mM n-butyrate, respectively, indicating a slowdown in cell progression through G2 and S. The duration of G2 was prolonged by 20, 70 and 140% at 1, 2.5 and 5 mM n-butyrate, respectively. The half-time of cell residence in G1A was increased by as much as 1.5- 6.3- and 15.6-fold by 1, 2.5 and 5 mM n-butyrate. Progression through late G1 (G1B) was not affected at 1 mM, and could not be estimated at higher drug concentrations. The effects on cell cycle progression were evident 1 h after addition of n-butyrate. DNA in situ in nuclei of n-butyrate-treated cells had lowered (by 2-8.degree. C) stability to thermal denaturation and increased (by 15%) accessibility to DNase I. The decrease in DNA stability to heat was more pronounced when permealized cells were heated in the presence of 1 mM MgCl2 rather than EDTA. DNA in situ in the nuclei of n-butyrate-treated cells also showed decreased sensitivity to acid-induced denaturation. Changes in chromatin were seen in all cells, regardless of cell cycle phase, within the 1st hours after addition of n-butyrate. Mitotic cells reacted to n-butyrate more rapidly than interphase cells. The observed changes in L1210 cells are most likely a consequence of histone modifications (acetylation of inner histones, dephosphorylation of histone H1) induced by n-butyrate.