title: 2'-Fluoro-modified phosphorothioate oligonucleotide can cause rapid degradation of P54nrb and PSF.
abstract: Synthetic oligonucleotides are used to regulate gene expression through different mechanisms. Chemical modifications of the backbone of the nucleic acid and/or of the 2' moiety of the ribose can increase nuclease stability and/or binding affinity of oligonucleotides to target molecules. Here we report that transfection of 2'-F-modified phosphorothioate oligonucleotides into cells can reduce the levels of P54nrb and PSF proteins through proteasome-mediated degradation. Such deleterious effects of 2'-F-modified oligonucleotides were observed in different cell types from different species, and were independent of oligonucleotide sequence, positions of the 2'-F-modified nucleotides in the oligonucleotides, method of delivery or mechanism of action of the oligonucleotides. Four 2'-F-modified nucleotides were sufficient to cause the protein reduction. P54nrb and PSF belong to Drosophila behavior/human splicing (DBHS) family. The third member of the family, PSPC1, was also reduced by the 2'-F-modified oligonucleotides. Preferential association of 2'-F-modified oligonucleotides with P54nrb was observed, which is partially responsible for the protein reduction. Consistent with the role of DBHS proteins in double-strand DNA break (DSB) repair, elevated DSBs were observed in cells treated with 2'-F-modified oligonucleotides, which contributed to severe impairment in cell proliferation. These results suggest that oligonucleotides with 2'-F modifications can cause non-specific loss of cellular protein(s).
authors: Department of Core Antisense Research, ISIS Pharmaceuticals, Inc. 2855 Gazelle Court, Carlsbad, CA 92010, USA.
authors: Wen
authors: W
authors: Shen
authors: Department of Core Antisense Research, ISIS Pharmaceuticals, Inc. 2855 Gazelle Court, Carlsbad, CA 92010, USA lliang@isisph.com.
authors: Xue-Hai
authors: XH
authors: Liang
authors: Department of Core Antisense Research, ISIS Pharmaceuticals, Inc. 2855 Gazelle Court, Carlsbad, CA 92010, USA.
authors: Hong
authors: H
authors: Sun
authors: Department of Core Antisense Research, ISIS Pharmaceuticals, Inc. 2855 Gazelle Court, Carlsbad, CA 92010, USA.
authors: Stanley T
authors: ST
authors: Crooke
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D004249:DNA Damage; D004268:DNA-Binding Proteins; D005461:Fluorine; D006367:HeLa Cells; D006801:Humans; D051379:Mice; D034521:Nuclear Matrix-Associated Proteins / Q000378:metabolism*; D009687:Nuclear Proteins / Q000378:metabolism; D050810:Octamer Transcription Factors / Q000378:metabolism*; D016376:Oligonucleotides, Antisense / Q000737:chemistry / Q000378:metabolism*; D000072670:PTB-Associated Splicing Factor; D054735:Phosphorothioate Oligonucleotides / Q000737:chemistry / Q000378:metabolism*; D055550:Protein Stability; D016601:RNA-Binding Proteins / Q000378:metabolism*
chemical_list: D004268:DNA-Binding Proteins; D005461:Fluorine; D034521:Nuclear Matrix-Associated Proteins; D009687:Nuclear Proteins; D050810:Octamer Transcription Factors; D016376:Oligonucleotides, Antisense; D000072670:PTB-Associated Splicing Factor; D054735:Phosphorothioate Oligonucleotides; D016601:RNA-Binding Proteins; C083214:NONO protein, human; C450059:PSPC1 protein, human; C500331:Nono protein, mouse