title: Tc-DNA modified siRNA.
abstract: We investigated the biological activity of siRNAs carrying tc-DNA modifications at various positions in the sense strand. The siRNAs were directed to the coding region of the enhanced green fluorescent protein (EGFP) mRNA. HeLa cells were transfected with the EGFP plasmid and variable concentrations of siRNA duplexes. The antisense effect was quantified on the protein level by fluorescence activated cell sorting (FACS). We found that 3'-end modification as well as modifications at 3-4 further positions either in the 3'- or the 5'-region of the sequence were well tolerated, some of them leading to higher repression of gene expression than wild type RNA.
authors.affiliation: Department of Chemistry & Biochemistry, Freiestrasse 3, CH-3012 Bern, Switzerland.
authors.forename: Damian
authors.initials: D
authors.lastname: Ittig
authors.forename: Daniel
authors.initials: D
authors.lastname: Schümperli
authors.forename: Christian J
authors.initials: CJ
authors.lastname: Leumann
mesh_terms: D049452:Green Fluorescent Proteins / Q000235:genetics; D006367:HeLa Cells; D006801:Humans; D009838:Oligodeoxyribonucleotides / Q000737:chemistry*; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000737:chemistry*
chemical_list: D009838:Oligodeoxyribonucleotides; D034741:RNA, Small Interfering; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins