Prime editing: advances and therapeutic applications

Clustered regularly interspaced short palindromic repeats-associated protein 9 (CRISPR–Cas)-mediated genome editing has revolutionized biomedical research and will likely change the therapeutic and diagnostic landscape. However, CRISPR–Cas9, which edits DNA by activating DNA double-strand break (DSB) repair pathways, is not always sufficient for gene therapy applications where precise mutation repair is required. Prime editing, the latest revolution in genome-editing technologies, can achieve any possible base substitution, insertion, or deletion without the requirement for DSBs. However, prime editing is still in its infancy, and further development is needed to improve editing efficiency and delivery strategies for therapeutic applications. We summarize latest developments in the optimization of prime editor (PE) variants with improved editing efficiency and precision. Moreover, we highlight some potential therapeutic applications.