Sakamoto Hojo E T, Balajee A S, Natarajan A T
Departamento de Biologia, Faculdade de Filosofia, Ciencias e Letras de Ribeirão Preto, Universidade de São Paolo, Brazil.
Mutat Res. 1994 Sep 1;309(2):165-73. doi: 10.1016/0027-5107(94)90089-2.
Exponentially growing CHO cells exposed to millimolar concentrations of sodium butyrate (SB) for 24 h were treated with AluI using two methods of cell poration, i.e., electroporation and streptolysin O (SLO). Under both conditions, SB was found to induce a 2-4-fold increase in AluI-induced chromosomal aberrations. When cells in monolayer were treated with AluI/SLO, lower concentrations of SB (2.5 mM) and AluI (1-4 U/ml) were required to produce a similar effect as that observed for electroporated cells, demonstrating the differential sensitivity of the two methods. Furthermore, in AluI/SLO-treated cells, a higher percentage of cells was found to show increased frequencies of aberrations per cell, compared to AluI/electroporated cells. The mechanism by which SB modulates the cell response to AluI treatment might involve changes in chromatin configuration thereby increasing the accessibility of AluI to different parts of chromatin.
将处于指数生长期的中国仓鼠卵巢（CHO）细胞暴露于毫摩尔浓度的丁酸钠（SB）中24小时，然后使用两种细胞穿孔方法，即电穿孔和链球菌溶血素O（SLO），用AluI进行处理。在这两种条件下，均发现SB可使AluI诱导的染色体畸变增加2至4倍。当单层细胞用AluI/SLO处理时，与电穿孔细胞相比，需要较低浓度的SB（2.5 mM）和AluI（1 - 4 U/ml）才能产生类似的效果，这表明两种方法的敏感性存在差异。此外，与AluI/电穿孔细胞相比，在AluI/SLO处理的细胞中，发现有更高比例的细胞显示每个细胞的畸变频率增加。SB调节细胞对AluI处理反应的机制可能涉及染色质构型的变化，从而增加AluI对染色质不同部位的可及性。
