Gene-sized editing for the therapy of genetic diseases

Programmable genome editing technologies have reshaped the landscape of biomedical sciences, enabling the development of methods with great translational potential. CRISPR-Cas represents one of the most important and widely adopted genome editing tools, although its reliance on double-stranded DNA breaks implies inherent limitations on the precision and safety of genomic insertions. Thus, several research groups have focused on the development of new editing technologies, among which prime editing has emerged as a cutting-edge system. Ongoing advancements in prime editing, including protein engineering, have enhanced its efficiency and expanded its functionality. However, prime editing cannot achieve integration of large DNA sequences larger than 5 kilobases. To overcome this limitation, PASTE and PASSIGE methods were developed as novel genome editing methods that merge precise genome rewriting with efficient recombinase-mediated gene insertion. In this review, we investigate the mechanistic principles of these systems, compare their performance in cellular and animal models, and discuss the ongoing efforts to enhance system components and delivery. We extended our investigation to recent progress supporting their translational potential, assessing efficient delivery methods, genome site specificity, safety, and long-term efficacy, which are crucial for successful in vivo applications.