Han Xiangzong, Fang Qiangyi, Yao Feng, Wang Xiaoning, Wang Jufang, Yang Shengli, Shen Bing Q
Graduate School of Chinese Academy of Sciences, Shanghai, China.
Cytotechnology. 2009 Jul;60(1-3):63. doi: 10.1007/s10616-009-9215-y.
Polyethylenimine has been used widely in transient gene expression with mammalian cells. To further understand its mediation of gene transfer, the transfection of HEK 293-F cells with dynamically prepared PEI/DNA complexes was studied with the help of fluorescent labeling. The efficiency of complex endocytosis/phagocytosis was found to correlate with the average sizes of complexes applied and complexes greater than 1 μm in diameter were likely excluded by the cells. Coupled with complex growth in size, the degree of association between PEI and DNA increased with the time of complex formation in the presence of competing ions. The blocking of transcription by complex formation necessitated complex dissociation in the nuclear environment for transcription to happen. Intracellularly, the fates of PEI complexed DNA therefore may be mostly determined by the degree of association. Results also suggested that the uptake of PEI/DNA complexes and subsequent protein expression were independent of the cell cycle stages of HEK 293-F cells.
聚乙烯亚胺已广泛应用于哺乳动物细胞的瞬时基因表达。为了进一步了解其介导的基因转移，借助荧光标记研究了用动态制备的聚乙烯亚胺/DNA复合物转染人胚肾293-F细胞。发现复合物的胞吞作用/吞噬作用效率与所应用复合物的平均大小相关，直径大于1μm的复合物可能会被细胞排除。随着复合物尺寸的增大，在存在竞争离子的情况下，聚乙烯亚胺与DNA之间的结合程度随复合物形成时间的增加而增加。复合物形成导致的转录阻断使得复合物在核环境中解离才能发生转录。因此，在细胞内，与聚乙烯亚胺复合的DNA的命运可能主要由结合程度决定。结果还表明，聚乙烯亚胺/DNA复合物的摄取及随后的蛋白质表达与HEK 293-F细胞的细胞周期阶段无关。
