期刊
MOLECULAR THERAPY
卷 16, 期 3, 页码 548-556出版社
CELL PRESS
DOI: 10.1038/sj.mt.6300399
关键词
-
资金
- PHS HHS [64274] Funding Source: Medline
Minicircle DNA vectors devoid of plasmid bacterial backbone, ( BB) DNAs, are transcriptionally persistent, whereas their parent plasmid counterparts are silenced in the liver. In this study we establish that circular plasmid BB provided in trans did not silence a transgene expression cassette in vivo, further confirming our previous conclusions that the covalent attachment of the plasmid BB to the expression cassette is required for DNA silencing. Given the high concentration of CpG dinucleotides in the plasmid BB, we investigated the role of DNA methylation on transgene silencing in vivo. The presence or absence of methylation in CpG motifs in routine plasmid BBs had no significant effect on transcriptional silencing. Furthermore, the removal of the CpG motifs from the BB did not ameliorate transcriptional silencing. Transgene silencing was partially inhibited when two tandem copies of the chicken cHS4 insulator at each end of a routine plasmid vector were used. These results are consistent with the idea that the transcriptional repression observed with plasmid DNA vectors in the liver is caused by formation of repressive heterochromatin on the plasmid DNA backbone, which then spreads and inactivates the transgene in cis, and that CpG content or methylation has little or no influence in the process.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据