Wu-Pong S, Bard J, Huffman J, Jimerson J
School of Pharmacy, Virginia Commonwealth University, Richmond 23298, USA.
Biol Cell. 1997 Jul;89(4):257-61.
Previous studies suggest that oligodeoxynucleotide (ODN) cellular uptake is cell cycle-dependent which may have important implications in cancer cell targeting. To further our understanding of ODN transport and activity, this study examines the relationships between the cell cycle, ODN cellular uptake, intracellular transport, and activity. An antisense c-myc ODN 21-mer was used to study ODN cellular uptake in Rauscher erythroleukemia cells synchronized by either chemical methods or flow cytometry. ODN uptake was examined using subcellular fractionation and confocal fluorescence microscopy. Western blot analysis was used to measure ODN-mediated decreases in c-myc protein levels. Intracellular ODN distribution and extent of uptake was influenced by the phase of the cell cycle, but the mechanism of uptake was not. The relative activity of the antisense ODN was positively correlated to ODN distribution to the cytosol, but negatively correlated to total cellular uptake. Although ODN total cellular uptake is positively influenced by the cell cycle, retention of the ODN in the cytosol (presumably extra-vesicularly) appeared to be relevant in determining the activity of an antisense ODN. Novel methods to target cytosol-acting drugs to the cytoplasm may therefore be warranted.
先前的研究表明，寡脱氧核苷酸（ODN）的细胞摄取是细胞周期依赖性的，这可能对癌细胞靶向具有重要意义。为了进一步了解ODN的转运和活性，本研究考察了细胞周期、ODN细胞摄取、细胞内转运及活性之间的关系。使用一条反义c-myc 21聚体ODN，研究通过化学方法或流式细胞术同步化的劳舍尔氏红白血病细胞中ODN的细胞摄取。采用亚细胞分级分离和共聚焦荧光显微镜检查ODN摄取情况。利用蛋白质免疫印迹分析来检测ODN介导的c-myc蛋白水平降低。细胞周期阶段影响细胞内ODN分布和摄取程度，但摄取机制不受影响。反义ODN的相对活性与ODN在细胞质中的分布呈正相关，但与细胞总摄取呈负相关。尽管细胞总摄取受细胞周期的正向影响，但ODN在细胞质中的保留（可能是囊泡外的）似乎与反义ODN活性的确定有关。因此，可能需要新的方法将作用于细胞质的药物靶向运送到细胞质中。
