Exploring synthetic lethality in cancer therapy: CRISPR-Cas9 technology offers new hope

Synthetic lethality (SL) is a breakthrough concept in cancer therapy that describes a scenario in which the simultaneous inactivation of two genes leads to cell death, whereas inactivation of either gene alone does not. The rise of clustered regularly interspaced short palindromic repeat (CRISPR)-CRISPR-associated nuclease 9 (Cas9) technology has provided a new tool for exploring this phenomenon, enabling genome editing and screening. This review evaluates the advancements achieved by CRISPR technology in identifying novel therapeutic targets and comprehending the processes of drug resistance using the concept of SL in cancer cells. This review explores the fundamental concept of SL and its application in cancer therapy, highlighting how the CRISPR-Cas9 system functions and how CRISPR-based screening can be leveraged to identify synthetic lethal genes and investigate the mechanisms of drug resistance. We summarize important research in related fields from recent years, demonstrating the role of CRISPR screening in revealing cancer cellular pathways and identifying new drug targets. We also summarize the clinical trials of related drugs currently underway, and anticipate that with the continuous development of CRISPR technology, its integration with cancer genetics and immuno-oncology will bring new hope to patients with drug-resistant cancers.