Prime Editing, CRISPR-Cas9, and NanoCas Genome Editing for Cancer Treatment

Over the past two decades, genome editing has advanced dramatically from Zinc Finger Nucleases (ZFNs) and Transcription Activator-Like Effector Nucleases (TALENs) to more refined systems such as CRISPR-Cas9, prime editing, and nanoCas technologies. These innovations have opened new frontiers in cancer treatment. This review aims to critically examine and compare recent advances in these genome editing platforms, with a focus on their molecular mechanisms, delivery challenges, oncological applications, and clinical prospects. We systematically explore how CRISPR-Cas9 enables gene knockouts, high-throughput functional genomic screens, and immune editing, while acknowledging its limitations due to off-target effects and genotoxicity. In contrast, base and prime editors offer precise, double-strand breaks (DSBs) free alternatives, suitable for correcting oncogenic mutations such as TP53, KRAS, and EGFR. Prime editing, although versatile, faces delivery and efficiency challenges. The emergence of nanoCas systems, derived from compact Cas orthologs, provides promising delivery advantages for in vivo applications. We also examine how tumor microenvironment, cell-type specificity, and immune barriers impact editing efficacy and safety. Strategies such as high-fidelity variants, optimized guide RNAs, and stimuli-responsive nanoparticles are discussed to enhance precision and minimize risk. Conclusively, integrating these genome editing tools into oncology requires addressing translational barriers while harnessing their precision and therapeutic potential for next-generation cancer treatments.