Base editing therapy forges ahead

CRISPR/Cas-based gene editing is an innovative biotechnology that has revolutionized genetic engineering in recent years. The process involves induction of a double-strand break (DSB) at the desired DNA site and subsequent cellular repair. Two primary mechanisms drive DSB repair: non-homologous end joining and homologous recombination-mediated repair. Non-homologous end joining, the primary mode of DSB repair, is a simple high-efficiency process that is susceptible to errors, and unpredictable nucleotide insertion or deletion mutations. In contrast, point mutations account for more than 50% of human genetic disorders and are the most frequent type of genetic variation in nature. Base editing is a precise gene editing approach in which a single DNA base is substituted without introduction of DSBs or use of a repair template. This technique has promising therapeutic potential in gene therapy, owing to its high efficiency and controllable editing results. Since the invention of the first base editing tools, the technique has rapidly developed and undergone clinical trials. This review summarizes progress in gene therapy through base editing, including DNA and RNA base editing, with particular emphasis on recent clinical trial and preclinical research advancements, current limitations and remaining challenges, and prospects for further research and applications.