Transplatin-modified oligo(2'-O-methyl ribonucleotide)s: a new tool for selective modulation of gene expression.
In the reaction between trans-diamminedichloroplatinum(II) and single-stranded oligo(2'-O-methyl ribonucleotide)s containing the sequence GNG (N being a nucleotide residue), the 1,3-trans-{Pt-(NH3)2[GNG]} cross-links are formed. The 1,3-intrastrand cross-links are inert within the single-stranded oligonucleotides. By contrast, they rearrange into interstrand cross-links when the platinated oligonucleotides are paired with their complementary RNA strands. The rate of the interstrand cross-linking reaction depends upon the sequence facing the intrastrand cross-links. When the complementary sequences are 5'-CN'C (N' being a nucleotide), the rates are rather slow (T1/2 >/= 3 h at 37 degrees C). The rearrangement of the intrastrand cross-links into interstrand cross-links can be achieved in a few minutes when the triplets facing the intrastrand cross-links are replaced by doublet 5'-UA or 5'-CA. In vitro, the specificity of the cross-linking reaction between a platinated oligo(2'-O-methyl ribonucleotide) and its target sequence (containing the 5'-CA doublet) located within the coding region of Ha-ras mRNA is demonstrated by steric blocking of reverse transcriptase and translation machinery. Within the HBL100ras1 cells, this platinated oligonucleotide binds specifically and irreversibly to the cognate Ha-ras mRNA. It also inhibits the proliferation of the HBL100ras1 cells in a dose-dependent manner. The fast and specific interstrand cross-linking reaction triggered by the formation of a double helix between platinated oligo(2'-O-methyl ribonucleotide)s and RNA enhances the potential of the oligonucleotides which do not induce mRNA cleavage by RNase H, to modulate gene expression by steric blocking of the translation machinery.
Boudvillain
M
M
Centre de Biophysique Moleculaire, CNRS, Orleans, France.
Guérin
M
M
Dalbiès
R
R
Saison-Behmoaras
T
T
Leng
M
M
D002455:Cell Division / Q000187:drug effects*; D002945:Cisplatin / Q000494:pharmacology*; D003432:Cross-Linking Reagents / Q000378:metabolism / Q000494:pharmacology; D004591:Electrophoresis, Polyacrylamide Gel; D015870:Gene Expression / Q000187:drug effects*; D011905:Genes, ras / Q000235:genetics; D006801:Humans; D009843:Oligoribonucleotides / Q000378:metabolism* / Q000494:pharmacology; D016133:Polymerase Chain Reaction; D012330:RNA, Double-Stranded / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism*; D012194:RNA-Directed DNA Polymerase / Q000378:metabolism; D014407:Tumor Cells, Cultured; D001613:beta 2-Microglobulin / Q000235:genetics
D003432:Cross-Linking Reagents; D009843:Oligoribonucleotides; D012330:RNA, Double-Stranded; D012333:RNA, Messenger; D001613:beta 2-Microglobulin; C034697:transplatin; D012194:RNA-Directed DNA Polymerase; D002945:Cisplatin