Chinese researchers develop ‘npegRNA’ that increases next-generation gene-editing efficiency 123-fold

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Chinese researchers have developed a new guide RNA that dramatically improves the efficiency of prime editing, a next-generation precision gene-editing technology, potentially broadening its application in therapeutics.

According to Chinese biotech media outlet BioOn and others on the 9th, a research team led by Professor Song Chunqing of Xihu University published the findings in the international journal Nature Biomedical Engineering on the 7th (local time).

Prime editing (PE) is considered a next-generation gene-editing technology with a favorable safety profile because it can replace, insert and delete bases without cutting the DNA double helix. However, its editing efficiency is low, and efficiency is even lower with ribonucleoprotein (RNP) delivery, which is preferred for therapeutic applications, limiting clinical use.

To overcome the limitations of conventional pegRNA, the research team newly designed a “noncanonical pegRNA” (npegRNA, non-canonical pegRNA). Unlike conventional pegRNA, npegRNA integrates the reverse-transcription template (RTT-PBS) required for gene editing into the guide RNA (sgRNA) loop structure.

The structural change made npegRNA more resistant to degradation by intracellular enzymes. As a result, the efficiency with which the prime-editing complex locates target DNA increased substantially, the research team explained.

In experiments using RNP delivery, npegRNA’s gene-editing efficiency was an average of 26.8-fold higher than that of conventional pegRNA and 5.9-fold higher than that of “epegRNA,” which had previously been developed to improve efficiency.

In particular, the efficiency of generating disease-associated mutations in human T cells (Jurkat) and induced pluripotent stem cells (iPSCs) increased by up to 123-fold. The therapeutic effect of correcting genes in a mouse model of tyrosinemia also improved.

“This study presents a powerful strategy for the therapeutic application of prime editing,” the research team said. “npegRNA will further increase the potential for developing gene-editing therapeutics.”