Caged siRNAs with 5' terminal modification for target gene regulation
【摘要】：Conditional regulation of siRNA functions will be highly useful, particularly through regulation of specific gene expression based on spatiotemporal resolution and amplitude.Here, we will reported the synthesis of a series of caged siRNAs with terminal modification of different targeting moeities, such as cholesterol, folic acid and cRGD. Although single terminal labelling with these moieties did not guarrenteed their entrance to cells, their modifications on 5 terminal of antisense strand of siRNA could effeciently inhibit their corresponding siRNA gene silencing activities. Upon exposure to light irradiation, the terminal moieties were removed and siRNA activity was recovered for target gene silencing.Using these terminal modified caged siRNAs, we could achieve photomodulation of targeting gene expression in cells and also spatial regulation of GFP expression. For cRGD modified caged siRNA, we could also GFP gene expression in live mice tumor model with U87-GFP cells.