Huxley C
Department of Biochemistry and Molecular Genetics, St Mary's Hospital Medical School, London, UK.
Gene Ther. 1994 Jan;1(1):7-12.
Effective therapy by in vivo delivery of DNA requires efficient delivery, long-term maintenance of the DNA that is delivered and physiological levels of expression of the therapeutic gene. Full levels of physiologically controlled expression can be obtained after transfer of intact genes on fragments of DNA hundreds of kilobases in size, as has been demonstrated by the transfer of yeast artificial chromosomes into transgenic mice. Long-term maintenance of input DNA could be achieved if the DNA carried replication origins, a centromere and telomeres to allow maintenance and segregation in mammalian cells, and there has been recent progress towards cloning these elements. These features could be combined as a mammalian artificial chromosome which would confer full levels of controlled expression as well as being maintained in any cell into which it was introduced. Methods which would allow delivery of such large fragments of DNA include liposomes and receptor-mediated uptake, both of which have been shown to work in vivo, making such large constructs potentially applicable for use in gene therapy.
通过体内递送DNA进行有效治疗需要高效递送、所递送DNA的长期维持以及治疗基因的生理水平表达。如将酵母人工染色体转入转基因小鼠所证明的那样，在转移数百千碱基大小的DNA片段上的完整基因后，可以获得完全生理控制水平的表达。如果DNA携带复制起点、着丝粒和端粒以允许在哺乳动物细胞中维持和分离，那么输入DNA的长期维持是可以实现的，并且最近在克隆这些元件方面已经取得了进展。这些特征可以组合成哺乳动物人工染色体，它将赋予完全控制水平的表达，并在所导入的任何细胞中维持。允许递送如此大的DNA片段的方法包括脂质体和受体介导的摄取，这两种方法在体内均已被证明有效，使得这种大的构建体有可能应用于基因治疗。
