Inhibition of Gene Expression by Triple Helix Formation in Hepatoma Cells (*)
Inhibition of Gene Expression by Triple Helix Formation in Hepatoma Cells (*)
复制标题
肝癌细胞中三螺旋形成对基因表达的抑制 (*)
DOI：
10.1074/jbc.270.47.28402
复制
发表时间：
1995
期刊：
影响因子：
--
通讯作者：
Y. Israel
中科院分区：
文献类型：
--
作者：
G. Tu;Q. Cao;Y. Israel
The aim of this study was to selectively inhibit human mitochondrial aldehyde dehydrogenase (ALDH) gene expression by triple helix assembly. Eight 21-mer oligodeoxyribonucleotides were designed to bind to two purine-rich sequences in the 5′-flanking region of the human ALDH gene. Gel mobility shift assays showed that triplex formation is sequence-specific for the target duplex and the third strand oligonucleotide. In the presence of Mg, but absence of K, triplex-forming oligonucleotides bind to their target sites with apparent dissociation constants (K) in the 10 to 10M range. Potassium cation virtually suppressed the triplex formation of G-C-rich duplex DNA with natural oligonucleotides, but did not prevent triplex formation with phosphorothioate-modified oligonucleotides. Phosphorothioate-modified oligonucleotides were delivered into human hepatoma Hep G2 cells by cationic liposomes. The reduction in ALDH mRNA levels in the cells was determined by the competitive reverse transcription-polymerase chain reaction. One of the phosphorothioate-modified oligonucleotides designed to form an antiparallel triplex with a target in the 5′-flanking region of human ALDH gene (−105 to −125 from the translation initiation codon ATG) reduced by 80-90% the ALDH mRNA levels without affecting albumin mRNA levels. Data suggest that triple-helix formation may provide a means to selectively inhibit hepatic ALDH gene expression for therapeutic use.
