Stimuli-responsive oligonucleotides in prodrug-based approaches for gene silencing
- Françoise Debart,
- Christelle Dupouy and
- Jean-Jacques Vasseur
Beilstein J. Org. Chem. 2018, 14, 436–469, doi:10.3762/bjoc.14.32
Graphical Abstract
Scheme 1: Demasking under reducing agents of ON prodrugs modified as phosphotriesters with A) benzyl groups [13] ...
Scheme 2: A) Synthesis via phosphoramidite chemistry and B) demasking under the reducing environment of 2’-O-...
Scheme 3: Synthesis via phosphoramidite chemistry of various 2’-O-alkyldithiomethyl (RSSM)-modified RNAs bear...
Scheme 4: A) siRNA conjugates to cholesterol [19] and B) PNA conjugates to a triphenylphosphonium [20] through a disu...
Scheme 5: Synthesis via phosphoramidite chemistry and deprotection mediated by nitroreductase/NADH of hypoxia...
Scheme 6: Synthesis via phosphoramidite chemistry and conversion mediated by nitroreductase/NADH of hypoxia-a...
Scheme 7: Incorporation of O6-(4-nitrobenzyl)-2’-deoxyguanosine into an ON prone to form a G-quadruplex struc...
Scheme 8: Synthesis and mechanism for the demasking of ON prodrugs from A) S-acylthioethyl phosphotriester [29] a...
Figure 1: Oligothymidylates bearing A) 2,2-bis(ethoxycarbonyl)-3-(pivaloyloxy)propyl- and B) 2-cyano-2(2-phen...
Figure 2: Oligothymidylates containing esterase and thermo-labile (4-acetylthio-2,2-dimethyl-3-oxobutyl) phos...
Scheme 9: Phosphoramidites and the corresponding RNA prodrugs protected as A) t-Bu-SATE, B) OH-SATE and C) A-...
Scheme 10: Mechanism of the hydrolysis of 2’-O-acyloxymethyl ONs mediated by carboxyesterases [46]. The hydrolysis...
Scheme 11: Synthesis of partially 2’-O-PivOM-modified RNAs [49] and 2’-O-PiBuOM-modified RNAs [53] using their corresp...
Figure 3: A) 2’-O-amino and guanidino-containing acetal ester phosphoramidites and B) 2’-O-(amino acid) aceta...
Scheme 12: Prodrugs of tricyclo-ONs functionalized with A) ethyl (tcee-T) and B) hexadecyl (tchd-T) ester func...
Scheme 13: Demasking mechanism of fma thiophosphate triesters in CpG ODN upon heat action [58].
Scheme 14: Thermolytic cleavage of the hydroxy-alkylated thiophosphate and phosphato-/thiophosphato-alkylated ...
Scheme 15: Synthesis via phosphoramidite chemistry and thermolytic cleavage of alkylated (diisopropyl, diethyl...
Scheme 16: Synthesis of thermosensitive prodrugs of ODNs containing fma thiophosphate triesters combined to po...
Scheme 17: Caging of deoxycytidine in methylphosphonate ONs by using the thermolabile phenylsulfonylcarbamoyl ...
Figure 4: Biotinylated 1-(5-(aminomethyl)-2-nitrophenyl)ethyl phosphoramidite used to cage the 5’-end of a si...
Scheme 18: Introduction and cleavage of 1-(4,5-dimethoxy-2-nitrophenyl)ethyl (DMNPE) [74] and cyclododecyl-DMNPE (...
Scheme 19: Post-synthetic introduction of a thioether-enol phosphodiester (TEEP) linkage into a DNAzyme by the...
Scheme 20: A) NPP dT and dG phosphoramidites [91,92] and B) NPOM U and G phosphoramidites [83] used to introduce photocag...
Scheme 21: Introduction of the photocaged 3-NPOM nucleobase into phosphorothioate antisense and morpholino ant...
Scheme 22: Control of the activity of an antisense ODN using a photocaged hairpin [82]. Formation of the hairpin s...
Scheme 23: Control of alternative splicing using phosphorothioate (PS) 2’-OMe-photocaged ONs resulting from th...
Scheme 24: A) Light activation of a photocaged DNAzyme incorporating 3-NPOM thymidine in its catalytic site [87]; ...
Scheme 25: Incorporation of 3-(6-nitropiperonyloxymethyl) (NPOM) thymidine and 4-nitropiperonylethyl (NPE) deo...
Scheme 26: Synthesis of a photocaged DNA decoy from a 3-NPOM thymidine phosphoramidite and release of the NPOM...
Scheme 27: Synthesis of a caged DNA decoy hairpin containing a 7-nitroindole nucleotide and release of the mod...
Figure 5: Caged-2’-adenosines used by MacMillan et al [93,94] (X = O) and Piccirilli et al [95] (X = S) to study RNA mec...
Scheme 28: Synthesis of circular ODNs containing a photolabile linker as described by Tang et al. [101,104].
Scheme 29: Control of RNA digestion with RNase H using light activation of a photocaged hairpin [97].
Scheme 30: Photocontrol of RNA degradation using caged circular antisense ODNs containing a photoresponsive li...
Scheme 31: Control of RNA translation using an “RNA bandage” consisting of two short 2’-OMe ONs linked togethe...
Scheme 32: Control of alternative splicing using photocaged ONs resulting from the incorporation of an o-nitro...
Scheme 33: A) Light deactivation of a photocaged DNAzyme incorporating one photocleavable spacer in its cataly...
Scheme 34: Solid-phase synthesis of a caged vit E-siRNA conjugate and its release upon UV irradiation [106].
Scheme 35: Synthesis of a siRNA conjugated to a nanoparticle (NP) via a cyclooctene heterolinker from a siRNA-...
