Effective gene-silencing of siRNAs that contain functionalized spacer linkages within the central region

Abstract

Short-interfering RNAs containing a variety of functional groups at the central region of the sense strand were synthesized and evaluated.

siRNAzos: A New Class of Azobenzene‐Containing siRNAs that Can Photochemically Regulate Gene Expression

“…In addition, the siRNAzos that contain the azobenzene internally within the central region ( 7 , and 9–12 ) all exhibit thermal destabilization as measured by UV‐monitored melting experiments (Table S‐1 in the Supporting Information). This is consistent with other studies that place thermally destabilizing units within siRNAs , − Finally, the siRNAzos all retained classic A‐type conformation, which is necessary for the RNAi pathway, as demonstrated by circular dichroism (Figure S‐1 in the Supporting Information).…”

“…Recently, we reported the synthesis and efficient RNAi knockdown by siRNAs that contain a variety of functionalized spacer linkages within its central region Of notable importance, was the effect of utilizing a biphenyl (BP) aromatic spacer linkage within this position . An siRNA bearing this modification within the central region of the sense strand of siRNAs exhibited potent gene‐silencing effects.…”

“…[18À19] Of notable importance, was the effect of utilizing a biphenyl (BP) aromatic spacer linkage within this position. [18] An siRNA bearing this modification within the central region of the sense strand of siRNAs exhibited potent gene-silencing effects. Given the success of the biphenyl modification, we hypothesized that azobenzene in the trans form would largely mimic the area occupied by biphenyl, and thus would lead to functional siRNAs.…”

Cellular Targeting of Oligonucleotides by Conjugation with Small Molecules

“…This therefore represents an adequate binding site for modifications and targeting ligands, further enhancing strand separation and altering the silencing of protein expression [ 49 , 50 ]. This is demonstrated in several examples [ 51 , 52 , 53 , 54 , 55 , 56 ]. A prominent representative of RNAi-triggering therapeutics is the first FDA-approved siRNA drug Patisiran [ 57 , 58 ] against hereditary transthyretin-mediated amyloidosis.…”

Effective carrier-free gene-silencing activity of cholesterol-modified siRNAs

“…[18][19][20] Recently, we reported a straightforward synthesis of a cholesterol phosphoramidite, bound covalently to a spacer via a triazole linkage. 21 This cholesterol-bearing spacer was then incorporated within the central region of the siRNA sense strand through solid-phase RNA synthesis. 21 Our biological studies in HeLa cells showed that these siRNAs were able to downregulate exogenous rey luciferase mRNA in a dose- dependent manner using the transfection carrier Lip-ofectamine® 2000.…”