Overcoming GNA/RNA Base-Pairing Limitations Using Isonucleotides Improves the Pharmacodynamic Activity of ESC+ GalNAc-siRNAs

We report the impact of two pairs of GNA nucleotides, the native GNA-C and -G compared with the isomeric GNA-isoC and -isoG, on the on- and off-target activity of chemically modified siRNAs in primary mouse hepatocytes by RNA sequencing. We found that both GNA-C and -isoC mitigate the suppression of off-targets in a similar fashion, however, GNA-isoG was less efficacious in the mitigation of off-targets as the native GNA-G. This study informs the further design of more potent and specific chemically modified siRNAs for potential application in RNAi therapeutics. This experiment intended to compare the specificity of several different chemicallly modified siRNAs after transfection into primary mouse hepatocytes and was aimed at demonstrating the similarities or differences between two pairs of chemically modified nucleotides when incorporated into the same position of an identical siRNA sequence.